posted by Anonymous .
When serving, a tennis ball is almost motionless when it is slammed by the racquet. A force sensor in an experimental tennis racquet measures a force of 80 N during the impact with a 0.058 kg tennis ball. The
impact lasts for 0.04 seconds. If the ball was at rest initially, what is its speed after the impact with the racquet?
v= F•Δt/m = 80•0.04/0.058=55.17 m/s