Name: ______Period: ______
Study Guide: Energy Transformations
1. What type of energy does a battery use?
Chemical energy is released when a battery is used– two chemicals are inside the battery that mix together to charge electrons.
2. What forms of energy are released (including wasted) when a hammer hits a nail?
When a hammer hits a nail, thermal (heat) and sound energy is released.
3. Name all of the forms of electromagnetic energy,
The types of electromagnetic energy are: radio waves, microwaves, infrared, visible light, ultraviolet, x rays, and gamma rays. The only type we can see is visible light.
4. When a rocket launches, what types of energy (including waste) are released? Which one can you feel?
When a rocket launches, the following forms of energy are released: mechanical (potential + kinetic), thermal (heat), visible light and sound. Thermal energy is the type that we can actually feel.
5. In the Sun’s core, hydrogen atoms combine together to form helium atoms. What type of energy is fueling the Sun?
Inside the Sun, hydrogen atoms hit each other at high speeds and fuse together. This releases the nuclear energy that fuels the Sun.
6. 100% Energy was placed in to a system. As transformations were made, there was only 95% of the energy left. What happened to it? Was it created? Destroyed?
When 100% of energy enters a system, some of it can escape. It is NEVER created or destroyed, just lost when it converts to different forms like light, heat and sound.
7. When a chemical reaction takes place and the substance becomes warm, what has happened?
Sometimes when chemicals are mixed together, they turn warm. The warmth is the release of thermal energy.
8. I have a lamp that that releases light and thermal energy. The lamp requires 100 watts of energy and of that, 50 watts are converted to light. How much was converted to thermal energy?
If my lamp requires 100 Watts of energy but only converts 50 Watts to light, then 50 Watts was converted to thermal (heat) energy. (I subtracted what went in from what came out as light; the left over was waste)
9. I have a radio that runs on batteries. If I left the radio on until the batteries ran out, what would happen to the radio’s energy?
If I left my battery powered radio running and the batteries died, the energy would NOT be created or destroyed – it would continue to travel through the atmosphere.
10. A rocket lifts off from Earth, on its way to Mars. The kinetic energy of the rocket is LESS than the potential energy. Explain why. Hint: what else does the potential energy in the fuel turn in to?
When a rocket lifts off, it has more potential energy than kinetic energy. There has to be more potential energy because there is going to be A LOT of wasted energy in the forms of light, heat and sound as the rocket makes it’s way higher into the atomosphere.
11. Draw an energy diagram for a flashlight being turned on.
An energy diagram for a flashlight would look like:
Chemical (batteries) – electrical (circuit is completed) - light (bulb lights up)
12. Draw an energy diagram for a toaster toasting bread.
An energy diagram for a toaster would look like
Electrical (plug) – thermal (heat toasts the bread)
13. What is efficiency?
If something is efficient, that means that it does a lot of work but does not create a lot of waste.
14. How would you know whether or not a light bulb is efficient?
I know that a light bulb is efficient because it will produce more light than thermal (heat) energy.
15. Why does energy get lost during a transformation? Where does it go?
Energy is lost during a transformation because waste products like heat, sound and light are also formed. This energy is NOT created or destroyed – it is simply lost in the air or atmosphere around it.
16. What is energy?
Energy is the ability to cause change.
17. Give an example of and object with mostly kinetic energy.
A car moving, a man running or a skateboarder at the lowest point on a ramp all have mostly kinetic energy.
18. Give an example of an object with mostly potential energy.
A ball at its highest point, a man on the top of a mountain, and a bird at the highest point in a tree all have mostly kinetic energy.
19. Does a delivery truck or a motorcycle have more kinetic energy? Why?
If a delivery truck and a motorcycle are both traveling the same speed, the delivery truck has more kinetic energy because of its size. More mass = more kinetic energy. More speed = more kinetic energy.
20. What is mechanical energy? Give an example.
Mechanical energy is the adding together of potential and kinetic energy in a system. A hammer hitting a nail and a roller coaster are examples of mechanical energy.