Name: _______________________________________
Vocabulary
Chapter 8 Worksheet Packet
Section 1 Vocabulary
1. work
2. power
3. joule
4. watt
Section 2 Vocabulary
1. machine
2. work input
3. work output
4. mechanical
advantage
5. mechanical
efficiency
pg. 1
Section 3 Vocabulary- define and draw a picture
1. lever
2. pulley
3. Wheel and
axle
4. Inclined plane
5. Wedge
6. Screw
7. Compound
machine
pg. 2
The Work Worksheet
Worksheet 8A
1. What is work?
2. For the following descriptions, write WORK if it is an example of work, and NOT WORK if
it is not an example of work.

A scientist delivers a speech to an audience of his peers. __________

A body builder lifts 350 pounds above his head. _________

A mother carries her baby from room to room. ___________

A father pushes a baby in a carriage. _______

A woman carries a 20 kg grocery bag to her car. _________
pg. 3
The Math Work Worksheet
Worksheet 8B
Modified from Colgurchemistry.com
(http://colgurchemistry.com/Science9/Physics/NEWPhysicsPDFs/Worksheet3_2Work%20and%20MA.pdf)
1. Please fill in the formal triangle below with the formula for work
2. In this formula, the unit for force is ____________ , the unit for distance is _________ and
the unit for work is __________.
3. 60 N of force is used to move an object a distance of 4.0 meters. Calculate the
amount of work done. Show your work. Include proper units in your answer.
4. An 800 N person is lifted a distance of 7.5 m. Calculate the amount of work done in
Joules. Show your work. Include proper units in your answer.
5. A person has a mass of 60 kg.
a. Calculate the gravitational force on the person. ____________________N
b. Calculate the amount of Work done if the person is lifted straight up a distance
of12 m. Show your work. Include proper units in your answer.
6. A force of 500 N is used to pull an object up an inclined plane. In order to move the
object, the total amount of work done was 1500 Joules. Calculate the distance the
object was moved. Show your work. Include proper units in your answer.
pg. 4
Worksheet 8B
7. 100 Joules of work was done to move an object with a force of 15 N. How far did the
object move?
8. How many centimeters did it move?
9. Amy uses 20N of force to push a lawn mower 10 meters. How much work does she
do?
10. Joe balances a stationary coin on the tip of his finger 20cm from the top of the table.
How much work is Joe doing?
11. A 900N mountain climber scales a 100m cliff. How much work is done by the mountain
climber?
12. How much work does an elephant do while moving a circus wagon 20meters with a
pulling force of 200N?
pg. 5
Power Practice Worksheet
Worksheet 8C
1. What is the formula for power?
2. What are the units for power?__________ For work? __________ For time? _______
3. How much power is required to pull a sled if you use 60J of work in 5 seconds?
4. A woman runs a kilometer using a force of 210N and a power output of 500W. How
long does it take this woman to complete 1 kilometer?
5. How long in minutes?
6. If it takes 5 seconds for you to do 1000J of work, what is your power output?
7. Frank does 2400J of work in climbing a set of stairs. If he does the work in 6 seconds,
what is his power output?
8. A small motor does 4000J of work in 20 seconds. What is the power of the motor in
watts?
pg. 6
Mechanical Advantage Practice
Worksheet 8D
1. Write the formula used to calculate Mechanical Advantage (MA)
2. Output force means the force _________________________________________________
3. Input force means the force ________________________________________________
4. It takes 100 N to pull an object up an inclined plane. The gravitational force on the
object is 600 N.
a. What is the input force in this case? ___________________N
b. What is the output force in this case? ____________________N
c. Calculate the Mechanical Advantage (MA)
5. A person has a mass of 80 kg. It takes a force of 150 N to pull that person up using a
system of pulleys.
a. Calculate the gravitational force on the person. __________________N
b. Calculate the Mechanical Advantage (MA) of the pulley system. Show all your
work.
6. The mechanical advantage of a lever is 6. How much force needs to be exerted on
the lever to lift an object with a gravitational force of 320 N? Show all your work.
7. It takes 130 N to push a 52 kg object up an inclined plane. Calculate the Mechanical
Advantage of the inclined plane. Show all your work.
8. In the space below, make up and solve your own problem using the formula for
mechanical advantage.
pg. 7
Efficiency of Machines Worksheet
Worksheet 8E
1. What is the formula used to calculate the efficiency of a machine?
2. What is the efficiency of a machine that requires 120J of input energy to do 35 J of useful work?
3. If a steam engine does 500 J of useful work, how much work is needed to be put in if the
efficiency rating of 18%?
4. What is the efficiency of a cyclist who expends 900J of work to his bike for it to produce 76 J of
useful work?
5. What is the efficiency of a tractor that has a work output of 300J and a work input of 400 J?
6. On planet Zorg, a Zorgian does 350N of useful work using his hortog. It he works at 25%
efficiency, what was the input work needed?
7. Which of the following machines is more efficient?
A. A stapler that has a work input of 55J and work output of 45J?
B. A stapler remover that has a work input of 66J and work output of 56J?
8. Which will have a greater work output?
A. A machine that has a work input of 250J and efficiency of 38%?
B. A machine that has a work input of 367J and an efficiency of 30%?
pg. 8