A tennis ball has a mass of 0.057kg. A professionaltennis player hits the ball h
ID: 1669739 • Letter: A
Question
A tennis ball has a mass of 0.057kg. A professionaltennis player hits the ball hard enough to give it a speed of50m/s(about 120mph). The ball hits a wall and bounces back withalmost the same speed(50m/s). The ball is crushed 2cm(0.02m) at theinstant when its speed is momentarily zero, before rebouding. Making the very rough apporximation that the large force that thewall exerts on the ball is approximately constant during contact,determine the approximate magnitude of this force. Hint : Thinkabout the approximate amount of time it takes for the ball to comemomentarily to rest.Explanation / Answer
FORCE=MASS*ACCELERATION acc=a=v*v-u*u/2s here v=-50m/sec u=50m/sec x=0.02m so force=0.057[-50-50]/2*0.02 =-142.5N magnitude of the force=142.5N