Question

A particle A is moving with a speed of 20 m/s towards right and another particle B is moving at a speed of 5 m/s towards right. Find their velocity of approach.

• A. 20 m/s
• B. 11 m/s
• C. 15 m/s
• D. 9 m/s

Answer 1

Answer: (C)

15 m/s

Answer is C.
Velocity of A, B and the difference in the velocities are given as follows.
$V_A=+20,V_B=+5$
$V_{AB}=V_A-V_B$ = $20-(+5)=15m/s$
Since separation is decreasing hence, $V_{app}=|V_{AB}|=15m/s$.