A tennis player places a 51 kg ball machine on a frictionless surface, as shown below. The machine fires a 0.067 kg tennis ball horizontally with a velocity of 33.4 m/s toward the north. What is the final velocity of the machine?

Answer 1

Newton's first law
Momentum before = 0
momentum after = momentum before = 0

51 v + .067 * 33.4 = 0

Answer 2

You got 0? how?

Answer 3

No, the sum of those two terms is 0

Answer 4

51 v = - .067*33.4
v = -.067*33.4/51

Answer 5

thanks i got it(: