Question

Two bodies $A$ and $B$ are travelling with constant velocities of $20\text{m/s}$ and $30\text{m/s}$ in opposite direction. The relative speed of $A$ with respect to $B$ is

• A. $10\text{m/s}$
• B. $20\text{m/s}$
• C. $30\text{m/s}$
• D. $50\text{m/s}$

Answer 1

The correct option is D $50\text{m/s}$

Velocity of body A and B is $20\text{m/s}$ and $30\text{m/s}$ respectively.
Relative velocity of A w.r.t B, $v_{AB}=v_A-v_B=20-(-30)=50\text{m/s}$