Potential Energy Gizmo

Calculationg Gravitational Potential Energy
1. a) The potential energy of the ball on the ground is 0J.
b) The potential energy of the paper is .31J.
c) If the paper is raised, its PE increases. If the paper is lowered, its PE decreases.
d) Horizontial movement has no affect on the PE of the paper.
e) The PE of the paperclips at the 2m shelf is .78J. The PE of the clips doubles at the 4m shelf to 1.57J.
f) I would expect the PE of the paperclips to be cut in half when they are lowered from the 2m shelf to the 1m shelf. Its PE is .39J at the 1m shelf.

2. a) PE of Ball: 1.96J Paperclips: 0.78J Paper: 0.16J
b) The ball has the greatest mass. The wad of paper has the smallest mass. The larger the PE the larger the mass.
c) The GPE is equal to mass times acceleration due to gravity (9.8 m/s) The Balls GPE is (1.96)=m(9.8)(2)) --> m=0.1g; The mass of the paperclips is (.78)=m(9.8)(2)) --> m=0.04g; The mass of the wad of paper is (0.16)=m(9.8)(2) --> m=0.009g
d) The PE of the clips is 1.96J at the 5m shelf; The PE of the wad of paper at the 3m shelf is 0.24J.


1. Ball Placed at the 1m Shelf
a) PE= 0.98J
b) PE at 4m = 3.92J
c) the PE quadrupled

2. Paperclips on the 5m shelf.
a)PE=1.96
b)PE at 3m =1.18
c) there are no other forces other than gravity acting on the paperclips. It is nagative because you are going from a higher level to a lower level.

3. Paper on the 2m Shelf
a)PE=0.16
b)PE=0.16
c)Net change of the paper is Zero. No work is being done by non-gravitational forces.

Physics Answers

From questions on http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/newtlaws/u2l4a.html

1. The fore is equal on both the firefly and the bus.

2. D) Rockets do accelerate in space because they push on the expanding gas.

3. C) the same size as the acceleration of the bullet.

4. C) the force is the same in each case.