Question

A body is falling under gravity. When it loses a gravitational potential energy by U, its speed is v. The mass of the body shall be

• A. $\frac { 2 U } { v }$
• B. $\frac { U } { 2 v }$
• C. $\frac { 2 U } { v ^ { 2 } }$
• D. $\frac { U } { 2 v ^ { 2 } }$

Answer 1

Answer: (C)

$\frac { 2 U } { v ^ { 2 } }$

Answer 2

Loss in potential energy = gain in kinetic energy

⇒ $m = \frac { 2 U } { v ^ { 2 } }$.