NOVA: Physical Science Workbook

PHYSICAL SCIENCE WORKBOOK

Core camp activity manual

NOVA CAMP Grade Level

6

7

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Copyright Š2020 by NOVA

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ISBN: 978-0-447-49429-5 Printed in the United States of America

First Edition 1 3 5 7 9 10 8 6 4 2

Table of Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . .

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THERMAL ENERGY . . . . . . . . . . . . . . . . . . .

6 6 8 8 8

Temperature . . . . .

Thermal Energy. . .

Thermal Transfer. .

Heat. . . . . . . . . . . .

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ACTIVITY . . . . . . . . . . . . . . . . . . . . . . . . . . .

Save that Ice . . . . . . . . . . . . . . . . . . . .

Instructions. . . . . . . . . . . . . . . . . . . . .

10 10 12

Glossary/Index . . . . . . . . . . . . . . . . . . . . . .

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Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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PHYSI

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ICAL SCIENCE Thermal energy is the internal energy of an object due to the kinetic energy of its atoms and/ or molecules.

Physical Science

7

TEMPERATURE

In the heat of science

Temperature Our everyday definition of Temperature is how hot or cold something is, but the actual definition of “temperature� is the average kinetic energy of molecules in a substance. The molecules in a liquid, solid, or vapor are always in motion. These molecules move around and bump into each other.

Because the molecules are moving, they have kinetic energy, and the faster the molecules move, the more kinetic energy they have. If you compare the molecules in a cup of hot cocoa to the molecules in a glass of cold chocolate milk, the hot cocoa molecules would be zipping around much faster than the cold chocolate milk molecules.

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Temperature the average kinetic energy of the molecules in a substance.

Measuring Temperature Usually, when things heat up, they expand, and when they cool down, they contract. Thermometers are based on the expansion or contraction of material according to temperature. When something is at a higher temperature, the liquid contained in the thermometer expands and indicates a higher temperature.

Converting Temperatures We usually measure temperature either in Celsius (C), which is the metric scale, or Fahrenheit (F).

Scientists use Kelvin (K) scale, which begins at the coldest point possible, called Absolute Zero.

Physical Science

9

THERMAL ENERGY

All of the potential The total amount of kinetic and potential energies in the molecules of a substance is its thermal energy. The difference between temperature and hermal energy is that temperature is the average kinetic energy of molecules in the substance, and thermal energy is the sum of the kinetic and potential energy of all of the molecules in a substance. For example, a single brick has less thermal energy than a stack of bricks because it has less potential energy, but the single brick and stack of bricks may have the same temperature.

Heat Heat is technically the transfer of thermal energy from a warmer substance to a cooler one. Thermal energy always moves from high to low energy, or, in other words, from warmer to cooler objects.

Thermal energy continues to transfer between substances until both are at the same temperature.

Thermal energy the sum of the kinetic and potential energies of all molecules in a substance.

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Thermal transfer The transfer of heat can occur through the following: Conduction: The transfer of heat from a warmer object to a cooler object through direct contact. The molecules in the warmer object collide with the slower-moving molecules in the colder object, transferring energy.

For example, touching a warm cup of team with your hands.

Radiation: The transfer of heat through electromagnetic rays. For example, the sun heating the earth or the warmth you feel when you sit next to a fire.

Convection: The transfer of heat through the movement of a fluid (such as air or water). Air in your home moves in convection currents —the warm air from a heater rises, cools down, then sinks back down to the floor.

You can enhance the flow of air (convection) with a ceiling fan.

MARIE CURIE was a Polish-French scientist who conducted pioneering research on radioactivity; a very dangerous form of thermal transfer.

Physical Science

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CHALLENGE

Save That Ice

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Goal

Materials

Before the invention of refrigerators, ice was stored in icehouses. Some were man-made underground chambers, while many were buildings with various types of insulation. For this challenge, you will design a shoebox-sized device that keeps three ice cubes from melting under a heat lamp for 30 minutes.

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Heat lamp Timer Ice cubes Carbboard or shoebox Masking tape Other materials to be determined by your research

Requirements

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Research: Write a one-to-two page paper summarizing your research in insulation and refrigeration. Use the space provided in this workbook.

Model: Label a drawing of your device design and explain your team’s strategy.

Results: Record, analyze and interpret test results.

Conclusion: Summarize the lab and what actually happened. I t should include the purpose, a brief description of the test procedure, and explanation of results.

Physical Science

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CHALLENGE

Instructions

1. Work with a team of 3-4 members.

2. Research insulation and refrigeration 3. Brainstorm ideas about how you might design an ice saver that meets the requirements of the lab. Think about how you will test your design.

4. Draw a diagram of your ice saver.

5. Construct the ice saver.

6. Test the design and record the results.

7. Evaluate the performance of your ice saver.

8. Identify how to improve your design.

9. Make the needed changes.

10. Retest and reevaluate your improved design.

11. Share the results.

Write your research here

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Use this space to design your ice saver

Physical Science

15

C

H

M

Coolant

Heat

A coolant is a substance, typically liquid or gas, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosion of the cooling system.

Some applications also require the coolant to be an electrical insulator.

Heat is the form of energy that is transferred between two substances at different temperatures. The direction of energy flow is from the substance of higher temperature to the substance of lower temperature.

Heat is measured in units of energy, usually calories or joules.

Heat and temperature are often used interchangeably, but this is incorrect.

Matter

I

F First Law of Thermodynamics: Conservation of Energy Heat — or energy — cannot be created or destroyed. It can, however, be transferred from one location to another and converted to and from other forms of energy.

Matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic particles, and in everyday as well as scientific usage, “matter” generally includes atoms and anything made up of them, and any particles (or combination of particles) that act as if they have both rest mass and volume.

Insulation Thermal insulation is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence.

Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials.

Melting Point The melting point of a substance is the temperature at which it changes state from solid to liquid.

At the melting point the solid and liquid phase exist in equilibrium.

The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.

Molecules A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.

Molecules are distinguished from ions by their lack of electrical charge. However, in quantum physics, organic chemistry, and biochemistry, the term molecule is often used less strictly, also being applied to polyatomic ions.

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R

T

Refrigeration

Temperature

Refrigeration is the process of removal of heat in a space, substance, or system to lower and/or maintain its temperature below the ambient one (while the removed heat is rejected at a higher temperature). In other words, refrigeration means artificial (human-made) cooling.[1][2] Energy in the form of heat is removed from a low-temperature reservoir and transferred to a high-temperature reservoir. The work of energy transfer is traditionally driven by mechanical means, but can also be driven by heat, magnetism, electricity, laser, or other means.

Refrigeration has many applications, including household refrigerators, industrial freezers, cryogenics, and air conditioning.

Temperature is the measure of hotness or coldness of matter.

Stated another way, temperature is the average kinetic energy per molecule of a substance.

Temperature is measured in degrees on the Celsius (C) or Fahrenheit (F) scale, or in kelvins (K). In simplest terms, temperature is how hot or cold an object is, while heat is the energy that flows from a hotter object to a cooler one. For example, the temperature of a cup of tea may feel hot if you put your hand around it. It is hot because heat from the tea is transferred to the cup.

Physical Science

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NOTES

Write notes here

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Notes

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