Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

9. + -14 points MI4 2.2.018. My Notes A tennis ball has a mass of 0.057 kg. A pr

ID: 1661193 • Letter: 9

Question

9. + -14 points MI4 2.2.018. My Notes A tennis ball has a mass of 0.057 kg. A professional tennis player hits the ball hard enough to give it a speed of 48 m/s (about 108 miles per hour.) The ball moves toward the left, hits a wall and bounces straight back to the right with almost the same speed (48 m/s). As indicated in the diagram below, high-speed photography shows that the ball is crushed about d 2.6 cm at the instant when its speed is momentarily zero, before rebounding Making the very rough approximation that the large force that the wall exerts on the ball is approximately constant during contact, determine the approximate magnitude of this force What is the average speed of the ball during the period from first contact with the wall to the moment the ball's speed is momentarily zero? avg I = m/s How much time elapses between first contact with the wall, and coming to a stop? What is the magnitude of the average force exerted by the wall on the ball during contact? In contrast, what is the magnitude of the qravitational force of the Earth on the ball? seconds mg = Additional Materials Section 2.2

Explanation / Answer

Constant force = constant deceleration = linear speed decrease.

So, vavg

=v0/2

= 24 m/s.


constant acceleration: t = 2s/v

= 2*.026/48

= 1.0833 ms

a = v/t

= 44309.05566 m/s²

F = m*a

= 2,525.616 N

Fg is 9.81*.057

= .56 N