A body is falling freely under the action of gravity alone in a vacuum. Which of the following quantities remain constant during the fall?
1.
kinetic energy
2.
potential energy
3.
total mechanical energy
4.
total linear momentum
(c) Hint: Apply the concept of conservation of energy.
As the body is falling freely under gravity, the potential energy decreases, and kinetic energy increases but total mechanical energy (PE + KE) of the body and earth system will be constant as an external force on the system is zero.
