Name
LESSON
Date
Outline
Work and Power
Use your textbook to help you fill in the blanks.
What is work?
1. According to its scientific definition, work occurs
force
when a(n)
move.
makes an object
transfers
2. Doing work on an object
energy to the object.
How is work measured?
3. Work is equal to the force of a push or pull multiplied
distance
by the
the object is moved.
4. When you multiply a force that is expressed in newtons
by a distance expressed in meters, the answer is
joules
expressed in newton-meters, or
.
5. The work done on an object depends on the
direction
the
of the force applied and
direction
of motion.
© McGraw-Hill Education
What is power?
work
6. Power is the amount of
divided by time.
done
7. Work is expressed in joules per second, or
watts
8. One
horsepower
Unit 6 • Work, Power, and Efficiency
Unit Resources
.
is equal to 746 watts.
Use with Lesson 1
Work and Power
6-5
LESSON
Name
Outline
Date
energy
9. Power is also equal to the amount of
transferred in a certain amount of time.
10. In a lightbulb, the
filament
converts electrical
light
energy into heat and
.
What is efficiency?
11. Any device that makes doing work easier is called
machine
a(n)
.
12. The force you use when you use a machine is called
input
the
force, or effort force.
13. When a machine makes an object move, the force the
machine applied and the distance the object moved
is called the
output
work.
efficiency
14. A machine’s
is the ratio of the
output work to the input work of the machine.
15. Friction converts some input work into thermal energy.
This is why a machine’s efficiency is always less than
100
percent.
Critical Thinking
To determine how much work the person did, you need to know
the force used by the person, in newtons, and the distance the ball
was rolled, measured in meters. The force used is multiplied by the
distance the ball was rolled to determine the amount of work done.
6-6
Unit 6 • Work, Power, and Efficiency
Unit Resources
Use with Lesson 1
Work and Power
© McGraw-Hill Education
16. A person rolled a large ball across a field. What information is
needed to determine how much work the person did?