Download CH 7 Study Guide-Answers

Name__________________________________________________ Date_________________ Period ___________
Chapter 7 Study Guide
Study guide due: ________________TB Pages due: ________________Test Date: ________________
Lesson 1
1. Define:
a. Energy – the ability to cause change
b. Work – the amount of energy used as a force moves an object over a distance
c. Kinetic Energy – energy due to motion
d. Potential Energy – stored energy due to the interactions between objects or particles
2. What is the difference between kinetic and potential energy?
Kinetic and potential energy are opposites of each other. When kinetic energy increases potential decreases. When
potential energy increases kinetic decreases (skate boarder example)
3. Kinetic energy depends on __speed___________ and __mass_________________.
4. Potential energy depends on ___weight_______ and ____height (and position)__.
5. What are three types of potential energy? Give an example of each.
a. _gravitational______________
example: holding a backpack in the air
b. ___elastic_________________
example: stretching a rubberband
c. __chemical________________
example: food, fuel, battery
6. What must happen in order for an action to be considered work?
An object must move in the direction the force is applied ex: pushing a chair across the room
7. What is the difference between energy and work?
Work cannot occur without energy. You use energy to do work, when the energy is transferred from one object to
another and it moves work is done
Lesson 2
1. Define:
a. Sound – energy that sound carries
b. Electric – the energy an electric current carries
c. Thermal – energy that involves heat from particles moving
d. Mechanical – energy that involves movement of parts ex: a clock, riding a bike
e. Nuclear – energy stored and released in the nucleus of atoms
f. Radiant – light energy, carried by electromagnetic waves ex: sun, light bulb
2. Law of Conservation of Energy – energy cannot be created or destroyed, it may only change form (transform) or
move from one object to another (transfer)
2. Explain how friction relates to thermal energy.
Friction is a force where 2 surfaces resist sliding. In thermal energy particles come into contact with each other. The
motions and interactions between the particles creates thermal energy.
3. Give examples of the following energy transformations:
Electric to thermal: coffee pot that has brewed coffee
Radiant to chemical: a plant going through photosythesis
Chemical to mechanical: eating and riding a bike
4. Explain the role of waste energy in energy transformations.
Thermal energy is part of energy transformation due to the movement of particles. Some of the transformed energy
cannot be used and this is waste energy.
Lesson 3
1. Define
a. Conduction – transfer of thermal energy by objects touching
b. Convection – transfer of thermal energy by particles moving from one part of a material to another part of
that material
c. Radiation-the transfer of thermal energy by electromagnetic waves
2. Give an example of
a. Conduction: ice melting, a refrigerator
b. Convection: boiling water, upstairs of house is warmer than downstairs
c. Radiation: heat lamp for a pet or food
3. Heat moves from a region of _warmer______ temperature to a region of __cooler___ temperature.
4. What is the difference between heat and thermal energy?
Objects contain thermal energy not heat. Once thermal energy moves, it is no longer considered heat.
5. Describe and give an example of each:
thermal insulator-material in which thermal energy moves slowly
example: gases are better than solids and liquids
Thermal conductor- material in which thermal energy moves quickly
example: most metals