Question

Boat travels upstream in a river and at t = 0 a wooden cork is thrown over the side with zero initial velocity. After 7.5 minutes the boat turns and starts moving downstream catches the cork when it has drifted 1 km downstream. Then the velocity of water current is –

• A. 2 Km/hr
• B. 4 Km/hr
• C. 6 Km/hr
• D. 8 Km/

Answer 1

Answer: (B)

4 Km/hr

Answer 2

Assume observer standing on water of flowing river.

Then, V_r = $\frac{d}{t}$ = 4 km/hr