A girl of mass 50 kg stands on a railroad car of mass 75 kg moving with velocity 20 m s - 1 . Now, the girl begins to run with a velocity of 10 m s - 1 with respect to the car in the same direction, as that of the car. The velocity of the car at this instant will be

Question

A girl of mass 50 kg stands on a railroad car of mass 75 kg moving with velocity 20 m s - 1 . Now, the girl begins to run with a velocity of 10 m s - 1 with respect to the car in the same direction, as that of the car. The velocity of the car at this instant will be, 20 m s - 1, 24 m s - 1, 16 m s - 1, 18 m s - 1

MARKS App · Accepted Answer

According to the law of conservation of linear momentum, P i = P f ⟹ 50 + 75 20 = 50 10 + v +​ 75 v ⟹ 125 × 20 = 50 10 + v + 75 v ⟹ 5 × 20 = 2 10 + v + 3 v ⟹ 100 = 20 + 2 v + 3 v ⟹ 5 v = 80 ⟹ v = 16 m s - 1

Search any question & find its solution

Looking for more such questions to practice?