Here's why:
* Mechanical Energy: This is the total energy of an object due to its motion and position. It's the sum of kinetic energy (energy of motion) and potential energy (energy due to position).
* Gravitational Potential Energy: This is the energy an object possesses due to its position in a gravitational field. It depends on the object's mass, height above a reference point, and the strength of the gravitational field.
* Kinetic Energy: This is the energy an object possesses due to its motion. It depends on the object's mass and velocity.
Scenario:
If an object is at rest, its kinetic energy is zero. Therefore, its mechanical energy is entirely due to its gravitational potential energy.
Example:
A ball held stationary above the ground has:
* Kinetic energy: 0 (because it's not moving)
* Gravitational potential energy: A value determined by its mass, height, and the gravitational acceleration.
* Mechanical energy: Equal to its gravitational potential energy.
Important Note:
If the object is moving, its mechanical energy will be greater than its gravitational potential energy because it will also have kinetic energy.
