Question

In a situation, a board is moving with a velocity $v$ with respect to earth, while a man A and man B are running with a velocity $2v$ with respect to earth and both men are running from the opposite ends of the board at the same time, as shown. Length of the board is $L$. If they meet after time $T$, then

• A. value of T is L/4v
• B. value of T is L/2v
• C. Displacement of man B with respect to board in time T is 3L/4
• D. Displacement of man A with respect to board in time T is L/4

Answer 1

Answer: (A), (C), (D)

value of T is L/4v
Displacement of man B with respect to board in time T is 3L/4
Displacement of man A with respect to board in time T is L/4

$VelocityofAwrtplank=VVelocityofBwrtplank=3VT=\frac{L}{V+3V}=\frac{L}{4V}Theirrelativedisplacementwrtplankare\frac{L}{4}\&\frac{3L}{4}respectively.$