5 minutes activities - datalogging

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5 Minute Activities Data Harvest Smart wireless ac�vi�es

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5 Minute Data logging Activities for Wireless sensors and loggers Prac�cal name

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01 - Temperature race

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02 - Cooling effect of evapora�on

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03 - Light - Transparent, translucent and opaque

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04 - Muffling sound

6

05 - Find the body!

7

06 - Thermal imaging

8

07 - Tes�ng for acidity

9

08 - Temperature and chemical reac�ons.

10

09 - Cola and Alka Seltzer reac�on

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10 - Pulse

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11 - Heart rate – armchair gymnas�cs

13

12 - The chocolate effect!

14

13 - Breathing

15

14 - Swea�ng

16

15 - Transpira�on: Water loss from plants

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16 - Reac�on �mes

19

17 - Hit the brakes!

21

18 - Timing cars

23

19 - Measuring speeds on a runway

24

20 - Accelera�on due to gravity

25

21 - Dynamo effect

26

22 - Dropping a magnet through a wire coil.

27

23 - Walk this way!

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24 - Measuring the speed of sound in air (Mo�on sensor)

29

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01 - Temperature race A simple short ac�vity using 2 Temperature sensors. Find out who can put more energy into a temperature S sensor over a one minute period. The data can then be used to explore the various analysis and display W mart ire les tools in the EasySense2 so�ware. s

What you need 2 Smart wireless Temperature sensors 2 volunteers Beaker of cold water.

What you need to do 1. Connect the Temperature sensors to your Bluetooth enabled device.

2. Use the default se�ngs and a graph template for the recording.

3. Each volunteer should pick up a temperature sensor and hold the �p in their hand. They should think of how they are going to warm the �p over the next minute. A�er a few moments thinking �me, start the recording.

3. To start the data recording click on start, to stop the recording click on stop.

4. Stop recording a�er 1 minute maximum.

5. Repeat as necessary or with a new pair of volunteers. If you want the data from many volunteers to be on the same graph make sure overlay is selected, otherwise each run will appear on a separate graph Tip. Watch out for anyone rubbing the �p of the sensor, it can generate enough heat to create a burn to the skin. Have cold water ready for the daredevil compe��ve volunteers.

Results •

Use Values to explore the data and find the maximum temperature for each line.

•

Use Difference to find the change of value from the beginning to the end of the graph for each line.

•

Use Area to find the area under the whole graph for both the sensors.

•

Shading lines will mark the sec�on under the graph for whichever sensor is currently selected on the Y-axis.

•

The area value for both sensors will be shown in the data value boxes.

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02 - Cooling effect of evapora�on This experiment shows the process by which the temperature of a liquid can be changed (evapora�on). It introduces the use of Overlay in the EasySense 2 so�ware.

Smart Wireless

Temperature sensors taped down but protruding with ends covered with small wads of co�on wool

What you need 2 Smart wireless Temperature sensors Very small pieces of co�on wool, or strips of absorbent �ssue Vola�le liquid such as propanol, a�er-shave or cologne Dropper or pipe�e S�cky tape to secure the Temperature sensors to a bench

What you need to do 1.

Assemble the apparatus as shown.

2.

Wind very small pieces of co�on wool to the protruding end of each Temperature sensor. The pieces should be the same size and shape.

3.

Connect the Temperature sensors to your Bluetooth enabled device.

4.

Use Setup to change the �me between samples to 1 second and select Overlay

5.

Click start to begin recording.

6.

Place 2 drops of of the vola�le liquid on one temperature sensor, leave the other dry as the control.

7.

Stop recording a�er 3 minutes.

8.

Replace the co�on wool used for the vola�le liquid with another same sized piece.

9.

Select overlay.

10. Repeat using another liquid.

Results Use Values, difference and interval, to find out how much the temperature changed, how long it took and the peak temperature change.

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03 - Light - Transparent, translucent and opaque Smart This ac�vity introduces SnapShot and uses a Light sensor to measure the amount of light blocked by Wireless a variety of materials.

What you need Light level sensor (set to the 0 – 1,000 Lux range) Light source (torch or mains lamp) Variety of materials (transparent, translucent and opaque materials e.g. clear polythene, coloured film, paper or card)

What you need to do 1.

Set up the apparatus with the light source poin�ng towards the Light sensor.

2.

Connect the Light sensor to your Bluetooth enabled device.

3.

Use Setup to create a data logging session that uses Snapshot data recording.

4.

Set the screen layout to have a graph panel and a table of results table.

5.

Start the data collec�on, a box will appear at the top centre of the centre screen. This tells you recording is ac�ve (green disc winks) and tells you to click the “Take a sample” bu�on to record the data.

6.

Click the “take a sample” bu�on to take the first measurement with no material between the light source and sensor. This will be the control reading.

7.

Place a sample of material in front of the light source and tap or click in the graph area to take the second measurement.

8.

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Repeat un�l all the samples have been tested. Select Stop

04 - Muffling sound

Smart Wireless

This ac�vity introduces the concepts that sound travels be�er through some materials than others and that some materials are be�er sound insulators than others.

What you need Smart Wireless Sound sensor set to the dBA range Large box and a variety of materials e.g. crumpled newspaper, polystyrene chips, fabric, wadding, bubble wrap, etc.

Noise maker e.g. Alarm clock.

What you need to do

Noise maker buried in box

1.

Connect the Sound sensor to your Bluetooth enabled device.

2.

The sound sensor has several ranges check the range is set to dB.

3.

Posi�on the Sound sensor above an empty box (use a clamp to hold in place).

4.

Use the default recording set up of the so�ware and a single graph layout.

5.

Click start to record and a�er 30 seconds stop the recording. This will be your control / baseline.

6.

Place a noise maker (clock, buzzer etc) into the empty box. Select Overlay and record 30 seconds of noise.

7.

Cover the noise maker with some sound absorbing material and repeat the recording.

8.

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Con�nue with as many types or designs of sound proofing you have available.

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05 - Find the body!

Sm Wi art rele ss

This ac�vity introduces the Infrared sensor and its ability to measure radiated heat as energy. When seeking living persons buried under rubble a rescue worker may use an infrared device to locate warm areas so they know where to dig.

In this ac�vity, a box of polystyrene chips represents rubble and the challenge is to ‘find the body’ (a bo�le of hot water).

What you need Smart wireless Infrared sensor – set to the irradiance range Box of polystyrene chips (or crumpled newspaper) Several small sealed bo�les of hot water Several small flags to act as markers

What you need to do 1.

Connect the Infrared sensor to the data logger. Open the so�ware and connect the data logger to your Bluetooth enabled device.

2.

The Infra Red sensor has mul�ple ranges. For this prac�cal the range needs to be set to irradiance, but experiment with other ranges for sensi�vity.

3.

Set up the apparatus and hide the hot water bo�les under the ‘rubble’.

4.

Use a meters chart in the so�ware.

5.

Click start and then scan the surface of the ‘rubble’ to locate a person – the measurements will rise significantly if a hot body is detected.

6.

Mark the ‘hot’ area with a flag and con�nue the search.

7.

When you have surveyed the whole apparatus Select Stop.

8.

Dig at the marked areas to see if you have correctly located any people (hot bo�les).

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06 - Thermal imaging This simple ac�vity introduces the Infrared sensor and its ability to measure radiated heat as

Sm Wi art rele ss

energy. NASA satellites use infrared sensors to create a thermal image of the earth. You will produce a graph of the residual heat radiated from a hand print on the laboratory bench.

What you need Smart wireless Infrared sensor – set to Irradiance Chalk or masking tape

What you need to do 1.

Layout a sample area to the dimensions shown in the diagram.

2.

Connect the Infrared sensor to the data logger.

3.

Open the so�ware and connect the data logger to your Bluetooth enabled device.

4.

You will use the default recording setup and a graph.

5. Rest the palm of your hand on the bench as shown, using the centre line as guide to place the hand in the centre of the 20 cm x 20 cm square.

6. Leave your hand in place for about 30 - 40 seconds, then remove.

7. Immediately press start and scan the sensor along the centre line taking about 20 seconds to complete the scan.

8.

Stop recording once you have reached the end.

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07 - Tes�ng for acidity This ac�vity introduces the pH sensor, as a method of finding out whether a solu�on is acid, alkaline or neutral and also the use of SnapShot, to record individual readings for comparison.

Test samples A to E

What you need A Smart Wireless pH sensor 6 beakers and various solu�ons (all at room temperature) to test e.g. A = soda drink, B = soap solu�on, C = vinegar, D = salt solu�on, E = lemon juice and F = sodium bicarbonate A beaker and wash bo�le of dis�lled water

What you need to do 1.

Open the so�ware and connect the pH sensor to you Bluetooth enabled device

2.

Use Setup to select SnapShot.

3.

Change layout to show to two charts. Set one to bars and one to a table.

4.

Start the recording. You will see

5.

Carefully put the pH sensor into the beaker containing solu�on A.

6.

When the reading from the sensor has stabilised, click the take sample bu�on at the top of the chart to record the data.

7.

Remove the sensor and rinse the electrode with dis�lled water, Repeat for the other samples you have been given.

8.

Click stop when you have run all tests

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open up.

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S Wi mart rel ess

08 - Temperature and chemical reac�ons.

This experiment uses the Temperature sensor to measure a small change during a chemical reac�on.

What you need A smart wireless Temperature sensor Beaker – 250 cm³ Warm water (37°C approx.)

1 teaspoon (5 cm³) of citric acid 2 teaspoons (10 cm³) of bicarbonate of soda

What you need to do 1.

Open the so�ware and connect the Temperature sensor to your Bluetooth enabled device

2.

Use the default se�ngs.

3.

Pour the warm water into a beaker and posi�on the temperature sensor in the water. Use a lid or a stand to hold the sensor in place.

4.

Start the logging and let it run for about 20 seconds.

5.

Add the bicarbonate to the water.

6.

Add the citric acid to the beaker (it will fizz up, it may reach the top of the beaker).

Results Use Values to explore the data.

Use Difference to find out how much the temperature changed.

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S Wi mart rel ess

09 - Cola and Alka Seltzer reac�on

S Wi mart rel ess Alka Seltzer effervescent Antacid tablets are taken to neutralize an acid stomach. In this experiment, you

will use the cola to represent an ‘acid stomach’ and compare the effect of a solid tablet against a crushed tablet.

What you need A Smart wireless pH Adapter and Electrode Beaker 250 cm³ 100 cm³ of cola ½ Alka Seltzer tablet - solid ½ Alka Seltzer tablet – crushed Dis�lled water

What you need to do 1.

Start the so�ware and connect the pH sensor to your Bluetooth enabled device.

2.

Use the default so�ware recording se�ngs.

3.

Add 100 cm3 of cola to the beaker and posi�on the pH electrode in the cola.

4.

Start the recording, leave it for a few seconds to get the base pH level of the cola, then add the uncrushed sample of Alka Seltzer.

5.

Record un�l the pH no longer changes.

6.

Stop recording.

7.

Select Overlay.

8.

Discard the cola and seltzer mix and wash the pH sensor.

9.

Add a new sample of cola to the beaker and repeat using the crushed sample.

Result Use Zoom or Autoscale to make the graph display fill the screen.

Use Gradient to determine the rate of reac�on.

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10 - Pulse This quick ac�vity introduces the heart waveform range of the Heart Rate Sensor and is the ideal introduc�on to any heart rate inves�ga�on.

W

ir Int eless erf ace

What you need V-series wireless data logger Heart rate sensor – set to the Heart wave (mV) range

What you need to do Connect the Heart rate sensor to the data logger.

1.

Clip the sensor onto your finger or ear lobe, wait un�l the LED on the sensor flashes on and off regularly.

2.

Select Start to begin logging and stay as s�ll as possible.

3.

When the recording has finished select Overlay.

4.

Clip the sensor onto another volunteer’s finger or ear lobe and repeat.

Results

1.

Use the series bar to hide any addi�onal sets of heart wave data by turning the coloured dots on and off.

You want to have only one graph line shown.

2.

Count the number of peaks over the 10 seconds, mul�ply by 6 to find the first person’s heart beats per minute.

3.

Repeat with the second person’s data.

Extension ac�vity Repeat this ac�vity a�er exercise to compare res�ng heart rate with exercising heart rate.

Note: There is a wide varia�on in people’s heart rates. If you have cold hands rub them together to improve the blood circula�on in the finger �ps before a�aching the sensor.

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11 - Heart rate – armchair gymnas�cs This ac�vity introduces the Heart Rate sensor, which can clip on either your index finger or earlobe. This Wi r simple heart rate sensor works well as long as it is kept s�ll and you are indoors.

Int eless erf ace

What you need

V-series wireless data logger Heart rate sensor set to Heart rate (bpm) range

What you need to do 1.

Connect the sensor to the data logger. Connect the logger to your Bluetooth enabled device.

2.

Clip the sensor onto your finger or ear lobe and wait un�l the LED on the sensor flashes on and off regularly.

3.

Sit comfortably and then select start to begin logging.

4.

Stay s�ll for 20 seconds and then raise your right hand for 20 seconds.

5.

Lower your right hand and stay s�ll for 20 seconds.

6.

Without moving your le� hand, stand up and stand s�ll for 20 seconds.

7.

Raise your right hand and wave it around for 20 seconds.

8.

Lower your right hand, sit down and stay s�ll for a final 20 seconds, then stop the recording.

Results Use scale (min max) to make the graph display fill the screen.

Ques�ons 1.

Does your heart always beat at the same rate?

2.

When did your heart beat fastest?

3.

What was your heart rate at the start?

4.

Was your heart rate at the end the same as at the start?

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12 - The chocolate effect!

This is a fun ac�vity based on the Heart rate sensor. We know that our heart rate alters as we exercise but this ac�vity explores something else that can alter our heart rate – ea�ng chocolate!

Wi r Int eless erf ace

What you need V-series wireless logger Heart rate sensor set to the Heart rate (bpm) range Chocolate (with a wrapper that rustles; it works be�er if it is obvious what they are ge�ng!)

What you need to do 1.

Connect the sensor to the data logger and the logger to you Bluetooth enable device.

2.

Clip the sensor onto your finger or ear lobe and wait un�l the LED on the sensor is flashing on and off regularly.

3.

Select Start to begin logging.

4.

Keep your finger s�ll and sit quietly for 30 seconds to record your res�ng heart rate.

5.

Take a bite of chocolate. Enjoy!

6.

Let the heart rate return to its res�ng rate and then take a second bite of chocolate.

7.

Stop the recording.

Results Use scale (min max) to make the data fit the screen.

Use Values to read the informa�on from the graph.

Ques�ons 1.

By how much did your heart rate change when you were ea�ng chocolate?

2.

Did your heart rate change as much during the second bite of chocolate?

Extension ac�vity Try another s�mulant e.g. caffeine in cola or Red Bull or hot drinks such as tea and coffee.

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13 - Breathing This ac�vity introduces the Oxygen sensor measuring the oxygen content of air. You will find out how much oxygen is consumed when you breathe in and out whilst si�ng quietly. You may then go on to compare the result with the oxygen consumed a�er a short burst of exercise.

Warning!

Only a single breath should be captured.

Do not re-breathe the air from the bag.

Make sure the bag has been completely emp�ed between uses to prevent re-breathing.

Sm Wi art rele ss

What you need Smart Wireless Oxygen.

Medium sized bag for breathing into

What you need to do 1.

You need no prepara�on for the Smart Wireless oxygen sensor, simply connect to your Bluetooth enabled device.

2.

Use a meter display to check the oxygen reading. If necessary use calibrate to set to 21%.

3.

Place the Oxygen sensor inside the bag and select start to begin logging.

4.

Take a deep breath and hold it for a slow count of 20 then breathe out slowly into the bag and then hold the bag shut.

5.

When the recording has finished remove the Oxygen sensor from the bag.

Results Use Values to find the minimum value or difference to find out how much the oxygen level changed.

Ques�ons How much difference was there between the start and the lowest value?

How much oxygen did you consume during one breath?

What other gases are exhaled when you breathe out?

Extension ac�vity Do some vigorous ac�vity e.g. running up and down stairs, then repeat the ac�vity and compare results.

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14 - Swea�ng When the Humidity sensor/cup is placed against the skin it will record the change of humidity

Wi

re caused by swea�ng. Once this effect has been experienced, you are ready to inves�gate whether Inter less fac e an�perspirants are effec�ve.

What you need V-series wireless data logger Humidity sensor Plas�c drinks cup (e.g. from water cooler) with a hole in its base Range of products to test e.g. Deodorant or An�perspirant – roll on liquid or cream Hazard Informa�on: Do not apply products to broken skin. If you know you are sensi�ve to any of the products being presented do not use them.

What you need to do 1.

Fit the cup onto the Humidity sensor and connect the sensor to the data logger. Start the so�ware and connect the logger to your Bluetooth enabled device.

2.

Click start to record the humidity in the room for the full two minutes. This is your control data which you will use for comparison.

3.

Wave the cup and sensor around to empty the “stale” air from the cup.

4.

Click on overlay and place the open end of the cup firmly either against the palm of your hand, or against the inner lower arm,

5.

Click on run and record for the same length of �me. This set of data will be the measure of swea�ng before any treatments.

6.

Wave the cup and sensor around to empty the “stale” air from the cup.

7.

Repeat the recording un�l you get a room, bare skin, an�perspirant treated and deodorant treated skin graph.

8.

Place and hold the cup firmly over the area where an�perspirant has been applied and select Start.

9.

Repeat with any other products supplied.

Results Use scale (min to max) to make the graph display fill the screen.

Use values to explore the data and use gradient to compare the rate of change of each line.

Ques�ons Which product performed best? Explain your answer.

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15 - Transpira�on: Water loss from plants This experiment uses the Humidity sensor to compare transpira�on from leaves of different plants.

Transpira�on is the engine by which water is drawn through the plant and up into the leaves. Plants use the water for photosynthesis and structural support. A lack of water will lead to wil�ng of the plant. Some plants wilt in the midday sun as a protec�on against water loss e.g. Beet plants.

Wi r Int eless erf ace

What you need V-series data logger Humidity sensor 2 x Plas�c beakers, one with a hole in the base 2 x Card discs with hole in the centre, or cling film Several leaves of similar size

Experiment apparatus

Control apparatus What you need to do 1.

Assemble the apparatus without the Humidity sensor or leaf in place. If cling film is used instead of card, make a small hole in the centre suitable for a leaf stem.

2.

Connect the Humidity sensor to the data logger. Open the so�ware and connect the logger to your Bluetooth enabled device.

3.

Posi�on the Humidity sensor over the card with a hole only, click on start and record for at least 2 minutes (this is the control)

4.

At the end of the recording, remove the upper chamber and wave the sensors and cup around to remove the “stale air” and return the condi�ons in the cup back to the room condi�ons.

5.

Select Overlay. Place the stalk (pe�ole) of Leaf 1 through the small hole, place the upper chamber and Humidity sensor in posi�on, select Start to record another set of data (use the same recording period).

6.

Repeat to test leaves 2 and 3 (or for as many leaves as you have available).

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Results Use Values and Difference to find the lowest humidity, highest humidity and the difference between the lowest and highest reading for each leaf type.

Leaf type

Lowest humidity

Highest humidity

Difference between the lowest and highest humidity

Ques�ons 1.

How does the size of the leaf change how quickly the humidity changes inside the chamber?

2.

Does the type of leaf have any effect on how quickly the humidity changes inside the chamber?

Extensions Use the same set up to: •

Inves�gate the effect of light on the rate of transpira�on.

•

Inves�gate from which side of the leaf transpira�on is greater. You will require 3 iden�cal leaves. Smear Vaseline on the top surface of one leaf, on the lower surface of the second leaf, leaving the third clear.

•

Inves�gate whether the transpira�on rate is the same for different types of leaf e.g. shiny leaves, silver leaves, hairy leaves, etc.

•

Does the colour of the light have any effect? Place a coloured filter (gel) between the light and the leaf.

Which colour has most effect?

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16 - Reac�on �mes This inves�ga�on will look at reac�on �mes and factors than may alter them. A reac�on �me is the quickest �me an individual can respond to a s�mulus.

Wi r Int eless erf ace

What you need V-series wireless logger 2 Push Bu�on Reac�on Switches (one of which must have LED)

an

Various items to use as distrac�ons e.g. sound source, mobile telephone etc.

What you need to do The tester and the responder each hold a switch. The tester presses their switch and the responder pushes the second switch as soon as he/she sees the LED light on the testers switch. This produces a �med response and the so�ware records the reac�on �mes as the �me from A to B. 1.Connect the switches to the inputs labelled A and B on the data logger (switch A is for the tester, switch B for the responder).

2.Connect the logger to your Bluetooth enable device.

3.Use setup to set the Timing up.

4.Make sure the responder can see the LED on the testers switch but cannot see any movement of the tester’s hand or fingers (A CD ROM stuck on the front of the switch with the LED showing through the centre hole works well).

5. Click run. The tester should press their switch; the responder should then press their switch as soon as they see the LED on the tester’s switch light up.

6.

Repeat several �mes to enable an average to be calculated.

Test 1 2 3 4 5 6 7 8

Time A to B

Average

Extensions •

Let the responder listen to some music on a pair of headphones and repeat the experiment.

•

Let the responder listen to a tape of instruc�ons that need following and repeat the test.

•

Let the responder have a drink containing caffeine, e.g. Cola or coffee to see if the reac�on �mes vary.

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Results The results will be presented as �me from A to B. This gives a direct value of the speed of reac�on. Be aware of the range of the �me scale used, as it is normal to express reac�on �mes as tenths or hundredths of a second.

Ques�ons 1.

How does your reac�on �me compare to the values printed in textbooks or on the web?

2.

Collect the averages for the rest of the group or class. Calculate the average for the class. How many people fall below the average? Is there a difference between genders? Calculate the average for female, and average for male responders.

3.

Find out about stopping distances from a textbook. Knowing your reac�on �mes, how far will you travel before stopping using the stopping values in the Highway Code at 30 mph, 40 mph and 50 mph?

4.

The test using taped instruc�ons simulate a phone call when driving. How did this test affect the reac�on �me and ul�mately the stopping distance?

5.

If you have access to a scien�fic calculator and have sufficient data, you can do a sta�s�cal test called standard devia�on. If you calculate the s.d. this will allow you to compare data from other reac�on �me experiments with more certainty.

Iden�fying errors Make a list of the possible sources of error in this experiment and then a�empt to quan�fy the errors in terms of how much they have affected the results.

Discuss the errors iden�fied with others to see if they are realis�c or come from preconceived ideas about reac�on �mes.

Notes on Standard Response: The gap between two neurons (the synapse) has physical proper�es that introduce a �me delay (latency) of approx. 10 ms per synapse. The neuron can carry the message at a maximum speed of 30 metres per second. Taking both these factors into considera�on, it would be unlikely to see a reac�on �me of below 0.02 seconds.

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17 - Hit the brakes!

This ‘reac�on �me’ inves�ga�on provides a simple model for the �me taken to depress the brake pedal of a car a�er a s�mulus.

Wi r Int eless erf ace

What you need V-series wireless data logger Push Bu�on Reac�on Switch Timing Mat Various items to use as distrac�ons e.g.sound source, mobile telephone

What you need to do 1. Reac�on �mes are recorded by the tester pressing the Push switch and the responder stepping on the Timing mat to produce a �med response.

2. Connect the tester’s push bu�on switch to input A on the data logger.

Connect the responder’s �ming mat to input B. 3. Connect the logger to your Bluetooth enabled device.

4. Use setup to set �ming to record �me from A to B. 5. Make sure the responder can see the LED of the tester’s switch but cannot see any movement of the tester’s hand or fingers (a CD ROM stuck in front of the switch with the LED showing through the centre hole works well).

The responder may need to stand in order to exert sufficient pressure on the Timing mat.

6.

Select Start. The tester should press their switch; the responder should stand on the Timing mat as soon as they see the LED on the tester’s switch light up.

7.

Repeat several �mes to enable an average to be calculated then select Stop.

Extensions •

Let the responder listen to some music on a pair of headphones and repeat the experiment.

•

Let the responder listen to a tape of instruc�ons that need following and repeat the test.

•

Let the responder have a drink containing caffeine, e.g. Cola or coffee to see if the reac�on �mes vary.

•

Compare the average ‘hi�ng the brakes’ �mes to the simple ‘reac�on �me’ test.

Data Harvest Smart wireless ac�vi�es

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Results The results will be presented as �me from A to B. This gives a direct value of the speed of reac�on. Be aware of the range of the �me scale used, as it is normal to express reac�on �mes as tenths or hundredths of a second.

Ques�ons 1.

How does your reac�on �me compare to the values printed in textbooks or on the web?

2.

Collect the averages for the rest of the group or class. Calculate the average for the class. How many people fall below the average? Is there a difference between genders? Calculate the average for female, and average for male responders.

3.

Find out about stopping distances from a textbook. Knowing your reac�on �mes, how far will you travel before stopping using the stopping values in the Highway Code at 30 mph, 40 mph and 50 mph?

4.

The test using taped instruc�ons simulates a phone call when driving. How did this test affect the reac�on �me and ul�mately the stopping distance?

5.

If you have access to a scien�fic calculator and have sufficient data, you can do a sta�s�cal test called standard devia�on. If you calculate the s.d. this will allow you to compare data from other reac�on �me experiments with more certainty.

Iden�fying errors •

Make a list of the possible sources of error in this experiment, and then a�empt to quan�fy the errors in terms of how much they have affected the results.

•

Discuss the errors iden�fied with others to see if they are realis�c or come from preconceived ideas about reac�on �mes.

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18 - Timing cars This inves�ga�on introduces the use of 2 Light gates to record accurately the �me taken for a car to travel from Light gate A to Light gate B. The so�ware will calculate the speed from A to B. Wi r Int eless erf ace

What you need V-series wireless logger 2 Light gates Dynamics track, cart and single interrupt card

What you need to do 1.

Set the dynamics ramp up with a slight slope, check the cart runs down the track easily but not too fast.

2.

Timing starts when the cart passes through light gate A

3.

Connect the Light gate the car goes through first to input A and the one it goes through second to input B on the data logger. Measure the distance between the two Light gates. Mark a Start line for the cars.

4.

Connect the logger to your Bluetooth enabled device.

5.

Use setup to set �ming to record speed / velocity from A to B.

6.

Click start. Let the first cart run down the slope, repeat several �mes to get a good average.

Extensions •

Try changing the height of the track and repea�ng the experiment.

•

Try adding mass to the cars and repeat the experiment.

Results Record in a table the �me and speed from A to B for each car plus the distance travelled.

Run

Time

Distance travelled

Ques�ons 1.

Why was it important to mark a start line?

2.

Which car had the fastest �me and which had the slowest �me?

3.

Can you offer an explana�on as to what made the difference?

4.

Does making the inclined plane steeper make any difference to the results?

5.

Is there a pa�ern when comparing the different heights and the average speeds?

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speed

19 - Measuring speeds on a runway When a trolley or toy car moves freely down a slope, it appears to get faster as it nears the bo�om. In this experiment, you will measure the speed of the trolley at different points along an inclined plane by moving the posi�on of the Light gate.

An interrupt card fi�ed to the car will break the Light gate’s beam. The so�ware records the �me that the beam is broken by the card. The length of the card is entered in the so�ware, which will then calculate the speed.

Wi r Int eless erf ace

Speed = Distance (length of card) Time (to go through the Light gate)

What you need V-series wireless data logger Light gate Dynamics track, cart and single interrupt card

What you need to do 1.

Assemble the apparatus, construct a catcher for the cart at the end of the track.

2.

Fix the Light gate close to the end of the track, make sure you have enough space a�er the Light gate to let the cart go all the way through.

3. Connect the Light gate to input A on the data logger.

4. Connect the logger to your Bluetooth enabled device.

5. Select Timing from setup and set up the recording to measure speed / velocity at A. You will need to enter the length of the single interrupt card on the cart.

6. Posi�on the cart 10 cm away from the Light gate and click on run.

Release the cart, it is best to stop the cart a�er it has gone through the light gate and not rely upon the catcher to stop the cart.

7. The speed will be shown on the graph.

8. Place the cart at the second posi�on on the slope (20 cm from the light gate), and repeat the experiment.

9. Repeat to get speeds from at least 4 distances.

Distance from Light gate

Speed / Velocity

Time at A

Ques�ons 1.

Compare the speed values at 10, 20, 30 cm etc. Is there a pa�ern in the way speed changes with distance?

Extensions •

Repeat the experiment with the slope at different heights. Does the shape of the graph change?

•

Does the mass of the trolley or car change the result? Load masses on to the trolley to find out.

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20 - Accelera�on due to gravity This inves�ga�on uses a double interrupt card and a single Light gate to measure accelera�on due to gravity.

Wi The card has two equal width segments. Timing measures the ini�al velocity as the first segment passes r Int eless through the Light gate and the final velocity when the second segment passes. The so�ware calculates erf ace accelera�on from the resul�ng change of velocity.

What you need V- series wireless data logger Light gate Retort stand and clamp Double interrupt card Ruler (mm divisions)

What you need to do 1.

Set up the apparatus as shown, connec�ng the Light gate to input A on the data logger. Mark up to 7 start posi�ons on the retort stand (posi�on 1 should be as close the Light gate as possible without breaking the beam).

2.

Connect the data logger to your Bluetooth enabled device.

Change the display to two panels, one for the �ming bars and one as a table of results.

3.

Set up �ming to record accelera�on at A with a double interrupt card.

4.

Click on start.

5.

Hold the �ming card at posi�on 1 and drop it through the Light gate.

6.

Repeat for each posi�on, ideally do three drops at each posi�on.

7.

Transfer the results to your own table of results and calculate the average accelera�on for each posi�on.

Posi�on 1

Posi�on 2

Posi�on 3

Posi�on 4

Posi�on 5

Posi�on 6

1 2 3 4 5 Average

Ques�ons 1.

Does the accelera�on of a falling object change as it falls to earth?

2.

As the �ming card was dropped from different heights, the ini�al and final veloci�es measured by the so�ware would have been different. Explain how different ini�al and final veloci�es can lead to the same calculated value of accelera�on.

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21 - Dynamo effect

S Wi mart rel ess

In this experiment a Voltage sensor is used to show the effect of spinning a magnet inside a wire coil – a simple dynamo.

What you need Smart wireless voltage and current sensor Wire Coil Strong magnet suspended on a string or rubber band

What you need to do 1.

Assemble the apparatus as shown in the diagram. Check that the magnet rotates in the centre of the coil!

2.

Connect the voltage and current sensor to the so�ware on your Bluetooth enabled device.

3.

Twist the magnet by 20 – 30 turns and hold it.

4.

Select start and release the magnet (if the magnet touches the side of the coil, adjust its’ posi�on, and restart data capture).

Ques�ons 1.

What was the maximum voltage created?

2.

How was the voltage related to the speed of rota�on of the magnet?

3.

How many revolu�ons did the magnet make? Explain your answer.

4.

What descrip�on is given to a voltage which changes like this?

5.

How fast was the magnet spinning (how many rota�ons per second?)

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22 - Dropping a magnet through a wire coil.

This simple and very fast ac�vity introduces the need for fast data logging.

What you need Smart wireless voltage and current sensor Wire coil Strong AlNiCo magnet A so� mat for the magnet to land on

What you need to do 1.

Assemble the apparatus as shown.

2.

Start the so�ware and connect the wireless voltage and current sensor to your Bluetooth enabled device.

3.

Make sure there is something so� for the magnet to fall onto.

4.

Use setup to give an intersample period of less than 50μs.

5.

When you are ready, click start and drop the magnet North pole first through the coil - take note of which pole you used first.

6.

Select Overlay and repeat. Make sure you drop the magnet from the same height each �me.

7.

Repeat the magnet drop with the magnet South pole first

Results Use tools to find the value of the maximum and minimum peaks.

Ques�ons 1.

Why are the peak values not the same?

2.

What is the difference between the graphs of the North pole first and the south pole first?

3.

Explain why the graph shows the two peaks as the magnet falls through the coil.

Extension.

Keep the pole you drop through the coil constant, but change the height from the drop point to the coil. What happens to the peak voltage value?

Use the same apparatus and measure the current induced.

Measure current and voltage at the same �me.

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S Wi mart rel ess

23 - Walk this way!

This inves�ga�on introduces the Mo�on sensor with a simple walking ac�vity. The Mo�on sensor is an ultrasonic sensor. It sends out an ultrasonic pulse and �mes how long each pulse takes to return to the sensor.

Wi r Int eless erf ace

What you need V-series wireless Data logger Mo�on sensor set to a distance range (1m or walk)

What you need to do 1.

Set up the Mo�on sensor as shown in the diagram and connect it to the data logger. Make sure you have enough space to move backwards and forwards without bumping into anything.

2.

Connect the logger to your Bluetooth enabled device.

3.

Stand about 1 metre away from the front of the sensor, and ask a partner to select start.

4.

Move forward slowly, stand s�ll and then move faster towards the sensor, then move backward to your start posi�on.

5.

When logging has stopped select Overlay. Ask your partner to copy your movements using your graph as a guide. When they are in posi�on select start.

6.

Repeat with other volunteers.

Results Use scale (min to max) to display the graphs more clearly.

Select which graphs to display or hide using the coloured series dots at the top of the graph.

Use Values to view the distance readings

Ques�ons 1.

Whose graph matched best with the original line?

2.

When you move faster, how does the distance-�me graph change?

3.

If you stand s�ll, what does the distance-�me graph look like?

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24 - Measuring the speed of sound in air (Mo�on W ir Int eless erf sensor) ace The Mo�on sensor measures distance by calcula�ng the �me for a pulse of ultrasound to travel to an object and return. We can therefore use it to calculate the speed of sound in air.

What you need V-series wireless logger Mo�on sensor - set first to the Time range then the Distance range Temperature sensor Calculator

What you need to do 1.

Connect the Mo�on sensor and the Temperature sensor to the data logger. Connect the logger to your Bluetooth enabled device.

2.

Select the Devices icon and change the range of the Mo�on sensor to Time.

3.

Click on the chart type icon in the top le� of the graph screen and change it from a graph to a meter display.

4.

Posi�on the Mo�on sensor as shown in the diagram, the distance (d) needs to be at least 1 metre measured from the sensors mesh to the surface. The flat surface needs to be a good reflec�ng surface (something “hard” like a wall or piece of card). Ensure the face of the sensor is ver�cal.

5.

Click start and the Meters display will show a reading of the �me it takes for the pulse to travel to the flat surface and back again (2d). The �me reading will be in microseconds (us). Keep a record of the �me and temperature.

6.

Select stop.

7.

Click on device and change the Mo�on sensors range to Distance (if you have mul�ple distance ranges chose the one closest to the distance being used. Click play and measure the exact (d) in metres.

Results Convert the reading from microseconds to seconds i.e. 1 microsecond = 10-⁶ seconds so divide by 1,000,000 e.g. 5855 μs = 0.005855 seconds.

Find the velocity of sound in metres per second. (Remember the pulse has travelled twice the distance recorded).

Extension: The velocity of sound changes with temperature. At 0°C the velocity of sound = 331.3 metres per second.

The velocity of sound increases at 0.607 metres per second per degree Celsius. (Ref Kaye and Laby) At 24 °C velocity of sound = (24 x 0.607) + 331.3 = 345.9 metres per second.

Compare your results with the standard.

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