Question

Jamal is at Six Flags playing at the arcade. At one booth he throws a 0.50 kg ball

forward with a velocity of 21.0 m/s in order to hit a 0.20 kg bottle sitting on a
shelf, and when he makes contact the bottle goes flying forward at 30.0 m/s
a. What is the velocity of the ball after it hits the bottle?
b. If the bottle were more massive (but flew forward with the same final velocity),
how would this affect the final velocity of the ball?

Answer 1

were solving for v velocity of the ball after it has hit the bottle. a. momentum ->p=mv->ball + bottle momentum during hit = ball + bottle momentum after hit-> ball (.5*21)+ bottle (.2*0) (it's 0 because the the bottle is standing still) = ball after hit (.5*v)+bottle after hit (.2*30) -> 10.5+0=.5v+6 ->4.5=.5v->v=9m/s

b. if bottle was heavier the ball would be slower so final velocity would decrease