Science, Primary 6, 1st term, Unit 1, lesson 1 : Mass & Weight

Science 6th primary 1st term Unit 1 lesson1

Mass and weight

First: mass Mass The amount of matter in an object.

The properties of mass : 12-

The mass of an object increases when the amount of matter in it increases and vice versa.

All matter have mass whatever their physical states (solids, liquids or gases)

3-

All matter have mass whatever their shapes (one piece, particles, powder , pure or mixture).

4-

All matter have mass whatever their places (in hand , on the moon or any other planet).

5-

The mass of any matter is a fixed (stable) value and it does not change by changing : a. the state of matter. b. the place of matter.

Example  

the mass measuring of any object on the Earth = the same mass in moon. mass never change by changing the place.

The measuring units of mass: Gram (g) It is suitable for measuring small masses such as jewellery.

kilogram (kg): It equal the mass of one liter of water at the normal temperature.

Ton: It is used to measure the very big masses.

It is suitable for measuring large masses as fruits and vegetables.

Prepared by Mr. Sabet Ibrahim

2019 / 2020

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Science 6th primary 1st term Unit 1 lesson1

The measuring devices of mass: Types of scales are Two arms scale 12-

One arm scale

Balance scale Sensitive scale

- digital scale.

- pointer scale.

Activity 1 How do you measure the mass of a solid object by a balance (two arms) scale.

Conclusion The mass = total mass of the standard masses.

Activity 2 How do you measure the mass of a liquid by balance or digital scale?

Conclusion Mass of liquid = mass of the glass with liquid – mass of empty glass.

Mass of liquid =

M2 - M1

** by increasing the object's mass, it is more difficult to move it.

Example

Locomotive has bigger mass than car, so the locomotive needs a stronger force to stop than what is needed for the car.

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2019 / 2020

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Science 6th primary 1st term Unit 1 lesson1

Second: Weight Answer the following question!!!! *** Are the children fall down when they jump up on the earth's surface? *** Does the astronaut fall down when he jumps from a high position in the space? *** if you carry your pen and leave it , while you are on the earth's surface, will it fall down? *** if the astronaut carries a pen and left it, will it fall down?

We conclude that : Object's falling downward on the earth because of a force called weight ((gravitational force)).

Weight:

It is the gravitational force by which a body is attracted to the earth. ď Ž effect of weight is always directed towards the center of the earth. ď Ž On earth. All objects have weight. But in space all objects are in a state of weightlessness.

So, Everything seems weightless inside the spacecraft which revolves around the earth.

**Newton is the measuring unit of weight.

Newton: It is the measuring unit of weight and almost equal to weight of an object on earth's surface whose mass is 100 grams.

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2019 / 2020

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Science 6th primary 1st term Unit 1 lesson1

Question??

What is mean by the mass of a small apple is 200 grams?

This means that the weight of this apple equals 2 Newton.

*** spring scale is the measuring device of weight: .

Activity 2 How can we measure the object's weight??? ** by using the spring scale by determining the extension of its spring.

The factors affecting weight: By three factors 123-

object's mass.

Planet (place) where the object exists.

Distance between the object and the center of the planet.

1-

the object's mass

Activity 3 To discover the relation between mass and weight.

Steps: 1-

measure the mass of the first object by using the balance scale and its weight by the spring scale.

Repeat the previous step with the other objects and write the results in a table.

Object's mass(kg)

1

2

3

4

5

Object's weight (Newton).

10

20

30

40

50

Prepared by Mr. Sabet Ibrahim

2019 / 2020

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Science 6th primary 1st term Unit 1 lesson1

Observation: Weight of object on earth increases by increasing the object's mass.

Conclusion: Weight (Newton) = Mass (kg) × 10 G.R: The relation between the weight of an object and its mass is directly relationship.

Exercise Calculate the mass of an object that its weight equals 90 Newton??

2 – the place where the object exists: As the mass of the planet (place) increases, the gravitational force for an object increases, so he weight of the object increases. *** the object weight differ when we change the place *** weight of object on moon = 1/6 of its weight on earth, because earth has greater mass and gravitational force than moon.

3 – distanc ebetween object and the center of the planet:

The weight of any body decreases when the distance between the body and the center of the planet increases as the gravitational force decreases.

Example Weight of a person in a balloon is smaller than that on earth as the gravitational force decreases.

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2019 / 2020

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Science 6th primary 1st term Unit 1 lesson1

comparison between mass and weight Point of comparison Definition

Mass The amount of matter in an object.

Measuring unit: Measuring device:

Kilogram or gram or ton.

Two-arm scales and one arm scales.

It has no effect

The direction o its effect:

The effect of changing the Constant. place:

Weight Mass Concept Amount Fixed value Physical states Particles Devices Scale Pointer Digital scale Standerd mass Locomotive

‫وزن‬ ‫كتلة‬ ‫مفهوم‬ ‫كمية‬ ‫قيمة ثاتبه‬ ‫الحالة‬ ‫الفيزيائيه‬ ‫جزيئات‬ ‫اجهزه‬ ‫مقياس‬ ‫مؤشر‬ ‫ميزان رقمي‬ ‫كتلة قياسيه‬ ‫قطار‬

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Vocabulary Extenstion Dawnwards Planet Determining Assign Direct Relationship Spring scale Spacecraft Weightlessness Revolve Gravitational Astronaut

2019 / 2020

Weight The gravitational force by which the body is attracted to the earth.

Newton.

Spring scale.

Its effect is always directed towards the center of earth (downward).

Variable.

‫امتداد‬ ‫لسفل‬ ‫كوكب‬ ‫يحدد‬ ‫يقيس‬ ‫مباشر‬ ‫علقة‬ ‫ميزان زنبركي‬ ‫مركبة فضاء‬ ‫عديم الوزن‬ ‫يدور‬ ‫جاذبية ارضية‬ ‫رائد فضاء‬

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Science 6th primary 1st term Unit 1 lesson1

Questions on lesson 1

Complete the following : 1-

………. is the amount of matte in an object.

2-

All matter have …………………….whatever their physical states, their shapes and their places.

3-

……………….. and ………………….are measuring units of mass.

4-

……………………. equals the mass of one paper clip, but ……………... Equals the mass of one liter of water at the normal temperature.

5-

……………kg = 8000 grams.

6-

Mass is measured by different types of scales as …. and ……….

7-

…………………….….. is used to measure the large masses as cheese and vegetables, while …………………………… is used to measure small masses.

8-

One arm scales are divided into ……………………..….. and ……………………..……….

9-

…………….…….. is the gravitational force by which a body is attracted to the earth.

10-

The effect of weight is always directed towards …………………………..

11-

The objects seem weightless inside the spacecraft due to the absence of …………….

12-

The measuring unit of mass is ……………. Or ……………… whereas the measuring unit of weight is …………..

13-

………………………….…. Is the measuring unit of weight.

14-

When mass of a small ball is 300 grams, so its weight equals………………….…….

15-

Spring balance determine ………………………..………

16-

Object's weight depends on ……………,……………and …………………………….….

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2019 / 2020

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Science 6th primary 1st term Unit 1 lesson1

17-

By increasing the mass of any object, its weight………………………………..….

18-

relation between the weight and mass is ………………………………..

19-

The weight of an object on the moon's surface equals …..…… of its weight on earth.

20-

The weight of a book on earth equals…………………..….. times its weight on moon.

Choose the correct answer 1 - ………………….. is the measuring units of mass.

A . gram b. kilogram c. ton

d. all the previous.

2 - …………………….. is the amount of matter in an object.

A: mass b. weight c. newton 3 - ………………….. equals the mass of one liter of water at the normal temperature.

A: kilometer b. kilogram c. ton d. meter.

4 – ……………………… is suitable for measuring large masses as fruits and vegetables.

A: kilogram b. gram c. ton d. meter.

5 – the mass of banana fruit on earth ……………………………………….

A: is similar to its mass on moon's surface. b. is smaller than its mass on moon's surface. c. is larger than its mass on moon's surface. d. is smaller than its mass on Jupiter surface.

6 - …………………….equal the mass of one paper clip.

A: kilogram b. gram c. newton

d. ton

7 - …………………………. Is the gravitational force with which a body is attracted to the earth.

A: weight b. mass c. newton d. balance scale 8 - ………………….. is the measuring unit of weight.

A: newton b. meter c. gram d. kilogram 9 - ………………………. Is the measuring device of weight.

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2019 / 2020

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Science 6th primary 1st term Unit 1 lesson1

A: spring scale

b. balance scale

c. one arm scale

10 – the weight of any body equals…………………………..

A: its mass b. its mass × 100 c. its mass × 10

d. two arm scale.

d. its mass ÷ 100

11 – the weight of any object ……………………… by increasing its mass.

A: decrease b. increase c. still constant d. no correct answer 12 - when the weight of bag on moon's surface equals 2 newton so, its weight on the earth's surface equals ……………………. Newton.

A: 12 b. 9 c. 2 d. 5 13 – the weight of any object …………………… when the distance between body and the center of the earth increases.

A: increases b. decreases c. constant 14 – by increasing distance between a person and earth …………………..

A : the gravitational force increases. b. the gravitational force decrease. c. the weight of person decrease. d. a and c

Give reasons for: 1 – the book has a mass? …………………………………………………………………………………………………………………………..

2 – the mass of pen on earth equals mass of the same pen on moon surface? …………………………………………………………………………………………………………………………..

3 – the weight of any object on earth's surface increases by increasing object's mass? …………………………………………………………………………………………………………………………..

4 – the weight of a bag in a balloon is smaller than that on earth? …………………………………………………………………………………………………………………………..

5 the weight of a person on earth is larger than on moon surface? ………………………………………………………………………………………………………………………

Prepared by Mr. Sabet Ibrahim

2019 / 2020

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