Question

Two bodies move toward each other from 10 m apart with a constant velocity they meet at C after 2s. What is the relative velocity of B w.r.t. A?

• A. 1 m/s
• B. -1 m/s
• C. 5 m/s
• D. -5 m/s

Answer 1

The correct option is D

-5 m/s

Velocity of B w.r.t. $A=U_{BA}$
We know $U_{BA}=U_B-U_A$
Where UB is velocity of B w.r.t. ground and UA is velocity of A w.r.t. ground
$\therefore u_B=\frac{-6}{2}=-3m/s$
$U_A=\frac{4}{2}=2m/s$
$U_{BA}=U_B-U_A=-3-2=-5m/s$