Gravitational potential energy negative?

[mrserv0n]

Can kinetic energy of a system or gravitational potential energy be negative?

I am reading about the two but its very complex and can't seem to describe why.

 

[Doc Al]

Kinetic energy must be positive, but gravitational PE can certainly be negative. Gravitational PE depends on what you choose as your (arbitrary) reference point, where you define PE = 0. (Only changes in PE are physically significant.)

 

[charng]

Yes, gravitational potential energy can be negative. This is because gravitational potential energy is a measure of the work done against gravity to move an object from a reference point to its current position. If the reference point is chosen to be at a lower potential energy than the current position, then the gravitational potential energy will be negative. This can happen, for example, if an object is dropped from a height and falls to the ground.

On the other hand, kinetic energy cannot be negative as it is a measure of the energy an object possesses due to its motion. Since motion cannot have a negative value, kinetic energy will always be positive. However, the change in kinetic energy can be negative if an object slows down or comes to a stop.

The complexity of these concepts may be due to their mathematical expressions and their relationship to each other. It is important to understand that both gravitational potential energy and kinetic energy are forms of energy, and they can be converted into each other. For example, when an object falls from a height, its gravitational potential energy decreases while its kinetic energy increases.

I hope this helps to clarify the concept of negative gravitational potential energy and its relationship with kinetic energy. Keep exploring and researching, as science is a never-ending journey of discovery and understanding.