AnswersPhysical ScienceWork, Power, and Energy

Work, Power, and Energy — Test Answers

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3

If the kinetic and potential energy in a system are equal, then the potential energy increases. What happens as a result?

A
Total energy decreases.
B
Energy of motion decreases.
C
Stored energy decreases.
D
Total energy increases.
5

What is needed for work to be done?

A
A force must act on an object while an equal force acts oppositely on the object.
B
A force must push on an object without moving it.
C
A force must cause an object to move along the same direction as the force.
D
A force must pull on an object without moving it.
6

What is the unit of measure for energy?

A
meters per second
B
watt
C
newtons
D
joules
7

Which activity directly converts energy from the Sun into chemical energy?

A
a snake lying on a sunny rock to keep warm
B
a person burning firewood to cook food
C
a bean plant making its own food to grow
D
a rabbit using energy from food it has eaten to run
9

When a person strikes and lights a match, potential energy in the match is transformed into which types of energy?

A
radiant and nuclear
B
nuclear and kinetic
C
thermal and radiant
D
electrical and thermal
10

Which term is the product of force and distance?

A
net force
B
power
C
work
D
acceleration
11

What is the source of almost all energy on Earth?

A
stored carbon
B
the Sun
C
moving water
D
Earth’s hot core
12

What are the two main types of energy?

A
radiant and chemical
B
thermal and radiant
C
potential and chemical
D
kinetic and potential
13

Tina and her puppy are tugging on a rope, each pulling on opposite ends. When is Tina doing work?

A
when she holds the rope steady as the puppy pulls it
B
the entire time she plays with the puppy
C
whenever she pulls the puppy toward her
D
when she lets go of the rope and the puppy pulls it away
14

Which two types of potential energies would be types of mechanical energies?

A
elastic and gravitational
B
electrical and kinetic
C
nuclear and chemical
D
radiant and thermal
16

Adita lifts a book from the floor, carries it across the room, and places it on a high shelf. When is Adita doing work on the book?

A
She does work only while she carries the book across the room.
B
She does work from the moment she touches the book until she lets it go.
C
She does work as she picks up the book and as she lifts it to the shelf.
D
She does work on the book at no time during this process.
17

Which is occurring when work is being done?

A
Energy is being reverted.
B
Energy is being increased.
C
Energy is being transferred.
D
Energy is being decreased.
18

Seema knows the mass of a basketball. What other information is needed to find the ball’s potential energy?

A
the volume and shape of the ball
B
acceleration due to gravity and the height the ball reaches
C
the volume and height the ball reaches
D
acceleration due to gravity and the shape of the ball
19

A gust of wind blowing east pushes against a ball. When will the wind do work on the ball?

A
when the ball moves north or south
B
when the ball moves to the north
C
when the ball stays in one place
D
when the ball moves to the east

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