Question

Momentum and Velocity

A wagon with a mass of 150kg moves (forceless) with a velocity of 8m/s. A group of 100 Kangaroos comes against it, each with a mass of 10kg and velocity of 4m/s. They jump on the wagon one after the other.

a) Whats the correlation of the wagon's velocity and momentum with the number of kangaroos on it? Sketch a graph for velocity and momentum. (Just roughly will do)

b) How many Kangaroos have to jump on the wagon so that the velocity of the wagon is 0. How large is the velocity after all the kangaroos are on the wagon?

c) How many Kangaroos would have to jump on the wagon so that it moves with the original velocity but in the opposite direction?

d) After all the Kangaroos are on the Wagon, they jump at the same time in the opposite direction of the motion of the wagon. Their velocity during the jump is 0 relative to the ground. 1) What's the jump velocity relative to the wagon? 2) What's the velocity of the wagon after the jump?

*I had trouble understanding if the velocity would decay linearly or exponentially. Just a general formula for b and c would be enough.

Answer 1