DATE:
NAME:
CLASS:
BLM 5-7
SKILL BUILDER
Potential Energy Is Relative
Goal • Practise solving problems that involve gravitational potential energy.
What to Do
Use the GRASP method to solve each problem. Use the following diagram to solve the first four problems.
1. The book in the diagram has a mass of 1.2 kg. If it falls from the shelf to the desk, what is the change in its
gravitational potential energy? Does it gain or lose gravitational potential energy?
2. If a student lifts the book from the chair and places it on the desk, how much potential energy does the book
gain or lose?
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DATE:
NAME:
CLASS:
BLM 5-7
SKILL BUILDER
Potential Energy Is Relative (continued)
3. What is the gravitational potential energy of the book on the desk relative to the floor?
4. If a 500 sheet package of paper has a gravitational potential energy of 22 J on the shelf relative to the desk, what
is the mass of the paper?
5. Assume that your mass is 57 kg. Your gravitational potential energy on top of Temple Mountain (altitude 3543
m) would be 1.13 × 106 J relative to Lake Louise. What is the altitude of Lake Louise? (Hint: Sketch a diagram
of the problem.)
6. A crate on a dock has a mass of 985 kg. A crane lifts the crate a distance of 8.1 m up from the dock and moves
it over the deck of a freighter. The crate then has 4.25 × 104 J of gravitational potential energy relative to the
deck. How much higher is the deck of the freighter than the dock?
Copyright © 2004 McGraw-Hill Ryerson Limited. Permission to edit and reproduce this page is granted to the purchaser for use in her/his classroom. McGraw-Hill Ryerson shall not
be held responsible for content if any revisions, additions, or deletions are made to this page.
DATE:
NAME:
CLASS:
BLM 5-7
SKILL BUILDER
Potential Energy Is Relative (continued)
7. The acceleration due to gravity on the Moon (gMoon) is 1.64 m/s2. An astronaut is about to climb out of her lunar
landing module. She is 2.8 m above the surface of the Moon. If her mass, including her spacesuit, is 71 kg,
what is her gravitational potential energy relative to the surface of the Moon?
8. Two skiers, with masses of 72 kg and 58 kg, are at the top of a ski hill in the mountains. The altitude at the top
is 3782 m. The altitude at a lodge below is 2926 m. How much more gravitational potential energy, relative to
the lodge, does the 72 kg skier have than the 58 kg skier?
Copyright © 2004 McGraw-Hill Ryerson Limited. Permission to edit and reproduce this page is granted to the purchaser for use in her/his classroom. McGraw-Hill Ryerson shall not
be held responsible for content if any revisions, additions, or deletions are made to this page.