1. Unit 3 CDA Review
Powerpoint Templates

2. An engine converts 95% of energy input into useful work output
An engine converts 95% of energy input into useful work output. What happens to the remaining 5% of energy?
Answer: It is converted to heat or to some other form of unusable energy.
What happens on every energy transformation?
Answer: Energy is conserved.

3. According to the Law of Conservation of Energy, what happens as a boy jumps from a rock and lands on the ground?
Answer: the total sum of potential and kinetic energy stays the same.
What happens to the kinetic energy and gravitational potential energy of a ball during free fall?
Answer: Gravitational potential energy
decreases and kinetic energy increase.

4. 5. According to the Law of Conservation of Energy, a bouncy ball should never stop bouncing. However, we know that it eventually stops. Where does some of the energy go?
Answer: Some of the energy is converted into sound energy and some is converted into thermal energy.
6. What is the energy transformation for burning gasoline in a automobile engine?
Answer: Chemical energy is transferred to mechanical energy.

5. Mary uses a lamp to read. Describe the energy transformation that takes place in the lamp
to help her read.
Answer: The energy is changing from Electrical to electromagnetic.
What type of energy is NOT at work when the flashlight SHINES?
Answer: Mechanical

6. As the fuel in a rocket burns, what can be said about the energy in the fuel and the energy in the moving rocket?
Answer: Chemical energy is lost from the fuel as the rocket gain kinetic energy.
10. Beating a drum represents what kind of energy conversion(transformation)?
Answer: Mechanical to sound

7. Plants transform electromagnetic energy from the sun into what kind of energy?
Answer: chemical energy
When all the energy source in a battery wears out, according to the Law of Conservation of Energy, what has happened?
Answer: All of the chemical energy in the battery has been transformed into other forms of energy.

8. Give an example of conduction.
Answer: A warm metal spoon cooling in a glass of ice tea.
If you held a piece of paper over a lamp that is on, what will happen to the paper and why?
Answer: The paper will spin because warm air rises.

9. Solar energy travels 150 million km from the Sun to the Earth
Solar energy travels 150 million km from the Sun to the Earth. How is the energy transferred through space?
Answer: through radiation
When you walk across a cold floor with bare feet, your feet become cold. What mostly causes your feet to become cold?
Answer: Thermal energy from your feet is moving to the cooler floor.

10. Bobby Sue is heating soup in a metal pan on top of the stove
Bobby Sue is heating soup in a metal pan on top of the stove. She noticed that it is about to boil over and grabs the handle. She quickly let go of the handle because it is burning her hand. What form of heat transfer did Bobby Sue experience?
Answer: Conduction
18. Shelby can have 5 appliances in her kitchen running at the same time. What type of circuit is she using?
Answer: a parallel circuit

11. 19. What is the advantage of a parallel circuit over a series circuit?
Answer: Resistance decreases as more pathways are added
A string of lights are lit. They are part of a series circuit. If one of the bulbs is removed, what happens to the rest of the lights?
Answer: They all go out.

12. What is a characteristic of a parallel circuit?
Answer: If one light goes out, the others burn the same as before.
What items can be used to make an electromagnet?
Answer: a nail, a piece of wire, and a battery

13. 23. How does a wire carrying an electric current exert a force on a bar magnet?
Answer: The wire carrying an electric current exerts a magnetic field.
If you push two of the same poles on a magnetic toward each other, what will happen?
Answer: The magnets will push away from each other.