Graviational Potential Energy
The Main Idea
Siimilar to potential energy caused by elastic potential, gravitational potential energy is caused by an object's position in a gravitational field relative to a chosen zero point.
A Mathematical Model
PE = mgh
- m = the object's mass in kilograms
- g = gravitational acceleration, 9.8 m/s^2 on earth
- h = the object's height in meters from a chosen reference point
Examples
What is the potential energy of a 5kg object on top of a 20 meter structure?
- PE = mgh
- PE = (5 kg) * (20 m) * (9.8 m/s^2)
- PE = 980 kg*m^2/s^2 = 980 J
Connectedness
Because of conservation of momentum, gravitational potential energy has many applications in physics, chemsistry, and several facets of engineering. For example, how fast will a ball hit the ground when dropped from a certain height? How much work is done by a tall waterfall? How high can you build a rollercoaster? Will roadrunner escape the perils of introductory physics (see video below)?
Video
References
- Matter & Interactions, Vol. II: Electric and Magnetic Interactions, 4nd Edition by R. Chabay & B. Sherwood (John Wiley & Sons 2015)
- Hyperphysics: Gravitational Potential Energy, Georgia Southern University