Question

energy conversions (pages 456–458)

1. as an object falls, the gravitational potential energy of the object is converted into
2. circle the letter of each sentence that is true about pendulums.

a a pendulum consists of a weight suspended from a string that swings back and forth.
b. the weight at the end of a pendulum reaches maximum kinetic energy at the highest point in the pendulum’s swing.
c potential energy and kinetic energy undergo constant conversion as a pendulum swings.
d. frictional forces enable a pendulum to continue swinging without slowing down.

1. at what point during a pole-vaulter’s jump is his gravitational potential energy the greatest?
2. circle the letter of the type of energy that increases as the pole bends before it propels a pole-vaultter up into the air.

a. kinetic energy b. mechanical energy
c. frictional force d. elastic potential energy

1. is the following sentence true or false? for a mechanical change in an isolated system, the mechanical energy at the beginning equals the mechanical energy at the end of the process, as long as friction is negligible.
2. tell whether the following situations illustrate kinetic energy, potential energy, or both.

|what type of energy is it?|

situation

form of energy

|a stationary wind-up toy with a compressed spring|
|a descending roller coaster car|
|a skier poised to take off at the top of a hill|
|a car driving on a flat road|
|a vibrating guitar string|
energy and mass (page 459)

1. what does einstein’s equation imply about mass and energy?
2. is the following sentence true or false? einstein’s equation, ( e = mc^2 ), suggests that mass and energy together are conserved.

reading and study workbook • chapter 15

Explanation:

Answer:

kinetic energy
a, c
at the highest point of the jump
d, elastic potential energy
true
potential energy, both, potential energy, kinetic energy, both
Mass and energy are equivalent and can be converted into each other.
true