First semester final exam

When you listen to music on your phone, which type of energy change is taking place?

• chemical energy to sound energy
• chemical energy to mechanical energy
• electrical energy to sound energy
• sound energy to electrical energy

In an effort to break a strip of aluminum metal, Charles bent it back and forth many times. He was surprised to find the aluminum getting warm at the point where the aluminum bend. This is an example of a transformation of

• heat energy to mechanical energy
• chemical energy to mechanical energy
• chemical energy to heat energy
• mechanical energy to elastic energu

A diver jumps off the high dive. Half way down how much mechanical energy does he have.

• 100%
• 75%
• 50%
• 25%
• 0%

In an effort to break a strip of aluminum metal, Charles bent it back and forth many times. He was surprised to find the aluminum getting warm at the point where the aluminum bend. The heating of the metal strip is

• a gain of energy
• the creation of heat energy
• the loss of heat energy
• unwanted energy from transformations

Identify the three objects in a group that can transform electrical energy into mechanical energy.

• vacuum cleaner, table saw, fan
• television, fan, refrigerator
• radio, clock, fan
• lawn mower, hair dryer, telephone

Electricity leaves the Hydroelectric generator at the power plant and travels through a wire to your home where it is transformed into mechanical energy in your vacuum cleaner. If 10 Joules of electrical energy are produced at the power plant, by the time this energy reaches the vacuum cleaner in your home and transformed into mechanical energy (assume the 10 joules is for the fan)

• slightly more than 10 joules of energy are produced by the vacuum cleaner
• less than 10 joules of energy are produced by the vacuum cleaner
• exactly 10 joules of energy are produced by the vacuum cleaner
• much more than 10 joules of energy are produced by the vacum cleaner.

Chemical to Mechanical energy transformations happen in both

• battery in a flashlight and you walking in the room
• battery in a toy car and lamp
• battery in a toy car and using a toaster
• a power lawn mower and using a toaster

Which item transforms 100 percent of energy it receives into useful energy?

• house fan
• battery in a flashlight
• hair dryer
• none of these

Dwayne opened the hood of his car after a long drive. He felt the warmth of the engine. The heat energy released by the engine is the process of moving the car is

• the primary energy output expected from a car engine
• the source of energy to make the car move
• produced by friction between wheels and the road
• produced as unwanted energy in the energy transformation process

Hitting a nail with a hammer involves using mechanical energy (swinging a hammer) to produce mechanical energy (moving the nail into the wood). As you hit the nail, you hear a banging sound, and if you touch the nail it feels warm. In this example, the sound and heat energy hitting the nail are

• helping to move the nail
• unwanted forms of energy
• not part of the energy transformation process
• newly created energy