Name:
edHelper
What Is Work?
What do you think work is? You might think that taking a test is work. But
scientists have something very specific in mind when they use the word "work." Work
is what is done whenever a force makes an object move some distance.
A force is a push or a pull. A force can cause an object to move that was standing
still before the force acted on it. A force can change the way an object moves.
Changing the direction of the force can make the object move in a different
direction. You can also change the speed of an object. You can make an object move faster by using more force.
You need different amounts of force to move different objects. The heavier the object, the more force you need
to move it. It would take more force to move a book than to move a piece of paper.
The amount of work you do depends on how much force you use. It also depends on how far the object moves.
Suppose you went outside and lifted a big rock. You would be doing work when you used force to make the
rock move any distance. Now suppose you lifted several rocks the same distance that you lifted the first one. You
would use more force to lift several rocks. You do more work if you use more force to move something the same
distance.
If you carried the first rock along with you on a long walk, you would be doing more work than if you only
moved it an inch or two. More work is done when the same amount of force moves an object a greater distance.
You can move around because you have energy-the ability to do work. You use energy whenever you use
force to move an object through a distance. The more work you do, the more energy you need. Your body
releases energy from the food you eat. You use this energy to do work. All objects that have energy can do work.
Suppose you are standing next to a brick wall, and you are pushing against the wall as hard as you can. Your
arms are getting tired from pushing so hard! Are you doing work?
No, you are not. You are not making the brick wall move any distance. You did not do any work.
Name:
edHelper
What Is Work?
Questions
1. ______ is done whenever a force moves an object over some distance.
A. energy
B. force
C. work
2. All objects that have ______ can do work.
A. work
B. energy
C. force
3. ______ is a push or a pull.
A. work
B. force
C. energy
4. A force:
A. can change the way an object moves
B. can cause a still object to begin moving
C. can change the speed or direction of a moving object
D. all of the above
5. ______ is used whenever work is done.
A. energy
B. work
C. force
6. You do more work when you move one object than if you move several objects the same distance.
A. false
B. true
7. You do more work when you move an object a farther distance than when you move the same object a
shorter distance.
A. true
B. false
8. If you are sitting still at school reading a book, you are doing work.
A. false
B. true
Name:
edHelper
How many of these can you write about? Think! Write! Check all the ones you answered.
When is energy used? Please explain and give an example.
How can a force cause an object to move? Please explain.
Do you think you do more work moving an object the same distance across a level floor or up a hill? Why?
Don't stop writing. Use a blank piece of paper to continue.
