2015 · Q34
A body is falling freely under the action of gravity alone in vacuum. Which one of the following remains constant during the fall?
General KnowledgePhysics
- APotential energy
- BKinetic energy
- CTotal linear momentum
- DTotal mechanical energy
Explanation
For a body falling freely under gravity alone in a vacuum, there is no air resistance, so no mechanical energy is lost: potential energy continuously converts into kinetic energy while their sum — the total mechanical energy — remains constant. Kinetic energy, potential energy, and linear momentum all change during the fall. Hence D.