The photograph in the figure below is a short-time exposure (1/31 s) of a juggler with two tennis balls in the air. (Take the diameter of the tennis ball to be 6.5 cm.)
(a) The tennis ball near the top of its trajectory is less blurred than the lower one. Why is that?
(b) Estimate the speed of the ball that he is just releasing from his right hand.
(c) Determine how high the ball should have gone above the launch point and compare it to an estimate from the picture. Hint: You have a built-in distance scale if you assume some reasonable value for the height of the juggler.