A man of 80 kg attempts to jump from a small boat of mass 40 kg on to the shore. He can generate a relative velocity of 6 m s- 1 between himself and the boat. His velocity towards the shore is

Question

A man of 80 kg attempts to jump from a small boat of mass 40 kg on to the shore. He can generate a relative velocity of 6 m s- 1 between himself and the boat. His velocity towards the shore is (A) 4ms- 1 (B) 8ms- 1 (C) 2ms- 1 (D) 3ms- 1

Tardigrade Admin · Accepted Answer

Let the velocity of boat be V opposite to the man. By momentum conservation, -40V+80(.6-V.)=0 ∴ V=4ms- 1 ∴ Velocity of the man =6-4=2ms- 1

Q. A man of $80 k g$ attempts to jump from a small boat of mass $40 k g$ on to the shore. He can generate a relative velocity of $6 m s^{- 1}$ between himself and the boat. His velocity towards the shore is

$4 m s^{- 1}$

$8 m s^{- 1}$

$2 m s^{- 1}$

$3 m s^{- 1}$

Let the velocity of boat be $V$ opposite to the man. By momentum conservation, $- 40 V + 80 (6 - V) = 0$
$∴ V = 4 m s^{- 1}$
$∴$ Velocity of the man $= 6 - 4 = 2 m s^{- 1}$

Q. A man of 80kg attempts to jump from a small boat of mass 40kg on to the shore. He can generate a relative velocity of 6ms−1 between himself and the boat. His velocity towards the shore is

4ms−1

8ms−1

2ms−1

3ms−1