Two boys, Jason and Keith are travelling on small trucks which are both coasting at 3ms-1 in the same direction along a straight horizontal track. Each boy and the truck he is standing on have a total mass of 120 kg. jason on the trailing truck has a medicine ball of additional mass of 5 kg which he is going to throw to Keith. The trucks are taken to have small frictionless wheels of negligible mass and air resistance is neglected.

(a) Find the total momentum of Jason, his truck and the medicine ball

(b) Jason throws the ball forwards so that it travels through the air with a horizontal component of 9 ms-1 towards Keith. Find the velocity of Jason after he has thrown the Ball.

(c) keith catches the ball. Find out how much faster than jason he is travelling after he has caught it.

My Attempt:

(a) 125 x3= 375N

(b) 120x3+5x9= 125V

405=125v ( I am not sure, Please help me)