Question

(a) Can the kinetic energy of an object be negative? If no, explain, if yes, give an example. (b) Can the potential energy of an object be negative? If no, explain, if yes, give an example.

Answer 1

a) No, the kinetic energy of an object cannot be negative. This is because KE=0.5mv². Any body cannot have negative mass and even if it has negative velocity, it becomes positive when squared. Therefore any body having kinetic energy has positive kinetic energy.

b) Yes, a body can have a negative potential energy. Potential energy is a concept based on the position of the object relative to the datum considered. If the datum is above the object, the object has negative potential energy. example: If the ground is considered as the datum, a ball in a well has negative energy.