A 0.057 kg tennis ball moving west at 24 m s is hit in the opposite direction east with a tennis racket. The force acting on the ball during the hit is shown in the graph below.
What is the magnitude of the final momentum of the tennis ball?
A. 0.63 kgm s B. 1.37 kgm s C. 1.80 kgm s D. 3.37 kgm s
f(tf-ti)=m(vf-vi)= change in momentum=impulse[/B]
The Attempt at a Solution
so I assumed that I could find final velocity going east by doing this
f ( tf - ti )= m ( vf - vi )
80 ( 0.06-0.02 ) = 0.057 ( vf - (-24) )
3.2 = 0.057 ( vf - (-24) )
56.14 = vf - (-24)
so momentum right is (0.057)(32)=1.824 kg*ms
left is (0.057)(-24)= -1.368 kg*ms
final is 1.824 + (-1.368) = .456kg*ms to the right
this is incorrect so I'm not sure where i went wrong, i'm sure its simple but it escapes me.
thanks for any insight