Question

If the force acting on a body is inversely proportional to its speed, then its kinetic energy is :

• A. Linearly related to time
• B. Inversely proportional to time
• C. Inversely proportional to the square of time
• D. A constant

Answer 1

Answer: (A)

Linearly related to time

Answer 2

Where C is a constant of proportionality.

Integrating both sides, we get

$\frac { \mathrm { v } ^ { 2 } } { 2 } = \frac { \mathrm { Ct } } { \mathrm { m } }$ or $\frac { 1 } { 2 } \mathrm { mv } ^ { 2 } = \mathrm { Ct }$

Or Kinetic energy, $\mathrm { k } = \frac { 1 } { 2 } \mathrm { mv } ^ { 2 } = \mathrm { Ct }$

Or