4. jake is bowling with a 8 kg bowling ball. he rolls the ball at 7 m/s, and it hits one stationary pin with a mass of 2 kg. the pin goes flying forward at 12 m/s. how fast is the bowling ball now traveling? m, vbefore + m v2 before = m, v, after +m, v2 after mass 1 before = velocity 1 before = velocity 1 after = mass 2 before = velocity 2 before = 0 m/s velocity 2 after =