Momentum Poblem.. Need help!! A 1.5 kg cart is propelled forward by a series of 85g balls being ejected from the rear of the cart with a speed of 3.5 m/s relative to the cart. Calculate the speed of the cart after three balls have been ejected. Compare this to the speed of the cart if it had ejected a signle 255g ball at 3.5 m/s relative to the cart. Assume negligible friction, calculate the final velocity for each cart? i have got an answer but the relationship is wrong the first cart should have the faster velocity... anyone help i need to understand this!!!