Understanding Potential Energy
Potential energy is the energy an object possesses due to its position or configuration. In this case, the rock has potential energy because of its height above the ground.
Formula
The formula for gravitational potential energy is:
PE = mgh
where:
* PE = Potential Energy (measured in Joules, J)
* m = mass (measured in kilograms, kg)
* g = acceleration due to gravity (approximately 9.8 m/s²)
* h = height (measured in meters, m)
Calculation
1. Identify the values:
* m = 20 kg
* g = 9.8 m/s²
* h = 100 m
2. Plug the values into the formula:
PE = (20 kg) * (9.8 m/s²) * (100 m)
3. Calculate:
PE = 19,600 J
Answer
The potential energy of the 20 kg rock placed at the top of the cliff is 19,600 Joules.
