Potential Energy
Gravitational Potential Energy — stored energy due to position: PE = mgh
What is happening to the kinetic energy of the disk as time passes?
II. Energy
(Joules) — 2 kinds
Potential & Kinetic Energy
A) Potential Energy - stored energy that an object has due to its position or condition.
“At what position(s) or condition(s) do these objects have the most PE?”
1. Gravitational P.E.g
(PE = Potential Energy)
Two factors determine PE
Height, weight
| P.E.g = | (mg)h = | (weight)h |
|---|---|---|
| Joules | Kg (m/s2)m | N m |
| (Not in reference) |
g on earth = 9.8 m/s2
mg = weight
(force it could exert)
h = height
(distance force could be exerted)
| ΔP.E. | = mgΔh | = wΔh |
|---|---|---|
| (Not in reference) |
Ex 1
What P.E. is gained when a 100. kg object is raised 4.00 m straight up?
m = 100. kg
h = 4.00 m
Ex 2
What PE would be gained if an object were moved 4 m to the right?
Ex 3
An object weighing 15. N is lifted from the ground to a height of .22 m.
Find object's change in PE.
w = 15. N
h = .22 m
| ΔP.E. | = mgΔh | = wΔh |
|---|---|---|
| (Not in reference) |
“Crow bars reduce the force needed to move a body”
“...remember what you learned on a seesaw?”
