Energy 1.0

Objects of different masses are suspended from a height. Which combination of features will have the greatest gravitational potential energy?

• low mass and low height

• low mass and high height

• high mass and high height

• high mass and low height

At which point(s) is the gravitation potential energy the highest?

• Point A

• Point C

• Points A and E

• Points B and D

At which point(s) is energy being transformed from kinetic energy of motion to gravitational potential energy as the skateboarder goes back and forth on the track?

• Point B

• Point D

• Points B and D

• Points A and E

At which point(s) is Kinetic Energy is the greatest?

• Point C

• Points B and D

• Points A and E

• Point D

Rubbing two wooden sticks together can sometimes result in a fire. What would increase the probability of a fire starting?

• using short sticks.

• holding the sticks higher off the ground

• rubbing the sticks together more quickly

• none of the above

Which statement most accurately describes the Law of Conservation of Energy?

• Energy is always lost during transformations and transfers.

• Energy is created from the Earth and is destroyed when we use it.

• Energy can not be created or destroyed but it can change from one type to another.

• Energy should be saved (conserved) for use in the future.

The efficiency of an average gasoline powered car is about 25%. This means,

• The gas tank needs to be 25% filled with gasoline for motion.

• The car uses 75% of the energy stored in the gasoline for motion.

• The car uses 25% of the energy stored in the gasoline for motion.

• The car wastes 25% of the energy stored in the gasoline.

What energy transformation(s) takes place when a laptop is plugged in and turned on?

• sound to thermal

• electrical to light, sound and thermal.

• solar to kinetic

• computer to video

Cory noticed that the hood of her gas-powered car was hot after driving it for a while. What energy transformation was she noticing?

• chemical energy → thermal energy

• thermal energy → motion (kinetic)

• temperature energy → braking energy

• motion (kinetic) → thermal energy

At which point(s) is Kinetic energy the greatest?

• Point W

• Point X

• Point Y

• Point W and Y