Question

A girl jumps out of a boat onto the riverbank at 3m/s. Her mass is 50kg and the mass of the boat is 300kg. What is the backwards velocity of the boat immediately after she has jumped off?

Answer 1

Step-by-step explanation:

The force F1 exerted by girl is the ‘action’ and the force F2 exerted by the boat is the ‘reaction’.

Now,

Momentum of the girl in one direction must be equal to the momentum of the boat in opposite direction.

$\longrightarrow \: m_1 × v_1 = m_2 × v_2$

$\longrightarrow \: 50 × 3 = 300 × v_2$

$\longrightarrow \: v_2 = 0.5$

Hence, velocity with which the boat begins to move backwards is 0.5 m/s