Question

A train travels at $60\text{m/s}$ to the east with respect to the ground. A businessman on the train runs at $5\text{m/s}$ to the west with respect to the train. Find the velocity of the man with respect to the ground.

• A. $5\text{m/s}$
• B. $55\text{m/s}$
• C. $60\text{m/s}$
• D. $65\text{m/s}$

Answer 1

The correct option is B $55\text{m/s}$

Assuming east as the positive direction.
Velocity of the train with respect to the ground $(v_T=60\text{m/s})$
Velocity of the man with respect to the train $(v_{MT}=-5\text{m/s})$
Let the velocity of the man with respect to the ground $=v_M$
$v_{MT}=v_M-v_T\Rightarrow v_M=v_{MT}+v_T\Rightarrow v_M=-5+60=55\text{m/s}$