CPN - Intro to Work

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C.PHYZ.WS.1                                                                                                  Work

    Work is a means by which energy can ____________ or ___________ an object or system.
    When work is done on an object, a force is applied to the object and the object undergoes a ______________
     in the _____________ direction as the force.
    Vector/Scalar? ______________
    Units: _______________

                    Calculating Work

1.   You exerted a force of 250 N in the horizontal direction which moved the crate in the horizontal direction 4 m.
     How much work did you do on the crate?

2.   A person exerts a great force of 500 N against a wall. How much work was done on the wall?

3.   A heavy suitcase weighing 100 N is carried a distance horizontally. How much was done on the suitcase?
1. For the following situations, determine whether work was done. Choose "work done" or "no
work done" for each situation.

I. An ice skater glides for two meters across ice.

II. The ice skater's partner lifts her up a distance of 1 meter.              _________________

III. The ice skater's partner carries her across the ice a distance of 3 meters.

IV. After setting her down, the ice skater's partner pulls her across the ice a distance of 10
meters.                  ________________

V. After skating practice, the ice skater lifts her 20 newton gym bag up 0.5 meter.

2. A woman lifts her 97 newton child up one          3. How much work does a mother do if she
meter and carries her for a distance of 50           lifts each of her twin babies upward 1 meter?
meters to the child's bedroom. How much              Each baby weighs 79 newtons.
work does the woman do?
4. You pull your sled through the snow a         5. Because the snow suddenly gets too slushy,
   distance of 500 meters with a horizontal      you decide to carry your 70 newton sled the
   force of 166 newtons. How much work did       rest of the way home. How much work do you
   you do?                                       do when you pick up the sled, lifting it 0.5
                                                 meter upward?

6. How much work do you do to carry the sled     7. A 502 newton gymnast jumps upward a
if your house is 800 meters away?                distance of 0.50 meters to reach the uneven
                                                 parallel bars. How much work did she do
                                                 before she even began her routine?

8. You lift a 31 newton bag of mulch 1.2         9. It took a 500.0 newton ballerina a force of
meters and carry it a distance of 15 meters to   217 joules to lift herself upward through the
the garden. How much work was done?              air. How high did she jump?
10. You did 150 joules of work lifting a 136      11. A bulldozer does 30,000 joules of work to
newton backpack. How high did you lift the        push another boulder a distance of 18 meters.
backpack?                                         How much force is applied to push the

12. An ant sits on the back of a mouse. The mouse carries the ant across the floor for a distance
of 10 meters. Was there work done by the mouse?                     Explain.

13. Which person did the most work? Show you rwork.

   I.      John walks 500 meters to the store. He buys 4.448 newtons of candy and then
           carries it to his friend's house which is 800 meters away.

   II.     Sally lifts her 22 newton cat a distance of 0.5 meter.

   III.    Henry carries groceries from a car to his house. Each bag of groceries weighs 40
           newtons. He has ten bags. He lifts each bag up one meter to carry it and then walks
           10 meters from his car to his house.

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