A man, jumping to the shore from a stationary boat, acquired an impulse of 240 kg m / s in the horizontal direction.

A man, jumping to the shore from a stationary boat, acquired an impulse of 240 kg m / s in the horizontal direction. What horizontal speed will the boat acquire when pushing with the foot if its mass is 80 kg?

To calculate the value of the horizontal speed acquired by the boat, we apply the law of conservation of momentum (we take into account that at the initial moment of time the boat was motionless): Ph = ml * Vl, whence Vl = Ph / ml.

Variables: Pp – impulse acquired by a person (Pp = 240 kg * m / s); ml – boat weight (ml = 80 kg).

Let’s perform the calculation: Vl = Ph / ml = 240/80 = 3 m / s.

Answer: After the push, the boat should acquire a horizontal speed of 3 m / s.