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A 0.635 kg basketball is dropped out of a window that is 6.07 m above the ground

ID: 2091400 • Letter: A

Question

A 0.635 kg basketball is dropped out of a window that is 6.07 m above the ground. The ball is caught by a person whose hands are 1.30 m above the ground. How much work is done on the ball by its weight? On a frozen pond, a 10.2 kg sled is given a kick that imparts to it an initial speed of v0 = 1.74 m/s. The coefficient of kinetic friction between sled and ice is ?k = 0.115. Use the work kinetic energy theorem to find the distance the sled moves before coming to rest. A basketball player makes a jump shot. The 0.584 kg ball is released at a height of 1.83 m above the floor with a speed of 7.37 m/s. The ball goes through the net 3.10 m above the floor at a speed of 4.26 m/s. What is the work done on the ball by air resistance, a nonconservative force?

Explanation / Answer

Under ideal conditions (no air resistance involved), the velocity of the ball as it goes up to the net is (determined by the formula)

Vf^2 - Vi^2 = 2gs

where

Vf = ideal velocity of ball as it hits the net
Vi = initial velocity of release
g = acceleration due to gravity
s = change in height
Substituting values we will get.



NOTE the negative sign attached to the acceleration due to gravity. This merely implies that the ball is slowing down as it is going up.

Vf^2

Vf .

Since the actual velocity of the ball is ---- meters, then the work done by air resistance is

Wr = difference in kinetic energy