Question

A particle moves in a straight line with retardation proportional to its displacement. Its loss of kinetic energy for any displacement x is proportional to

• A. $x ^ { 2 }$
• B. $e ^ { x }$
• C. x
• D. $\log _ { e } x$

Answer 1

Answer: (A)

$x ^ { 2 }$

Answer 2

This condition is applicable for simple harmonic motion. As particle moves from mean position to extreme position its potential energy increases according to expression $U = \frac { 1 } { 2 } k x ^ { 2 }$ and accordingly kinetic energy decreases.