Consider the problem of returning a serve in tennis. a serve is hit at a speed of 67.7 m/s, and is hit back to the server with a speed of 40.8 m/s. the ball of mas m = 57 g is in contact with the racket for 0.01s.
(a) what is the magnitude of the impulse imparted to the ball as it is returned to the server?
(b) estimate the magnitude of the average force on the ball.

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.