Which of the following statements is/are correct for a freely falling body? I. the total is entirely kinetic II. the ratio of potential energy to kinetic en...
Which of the following statements is/are correct for a freely falling body?
I. the total is entirely kinetic
II. the ratio of potential energy to kinetic energy is constant
III. the sum of potential and kinetic energy is constant
Answer Details
The correct answer is "III only".
A freely falling body is one that is falling under the influence of gravity and experiences no other force or constraint. In this situation, the total energy of the body is conserved, meaning that the sum of its potential and kinetic energy remains constant. The potential energy of a body is directly proportional to its height above the ground, and its kinetic energy is directly proportional to its velocity. As the body falls, its potential energy decreases and its kinetic energy increases, but the total energy remains constant.
Statement III is correct because the sum of potential and kinetic energy is indeed constant for a freely falling body.
Statement I is incorrect because the body has both potential and kinetic energy, so the total energy is not entirely kinetic.
Statement II is incorrect because the ratio of potential energy to kinetic energy is not constant for a freely falling body, as both are changing as the body falls.