# college physics

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A 147 g baseball is dropped from a tree 12.0 m above the ground. If it actually hits the ground with a speed of 8.00 m/s, what is the magnitude of the average force of air resistance exerted on it?

• college physics -

The air resistance is not constant, but increases in proportion to V^2.

The best you can do is compute an average air resistance during the fall. You would do this by computing the work done against air friction and dividing it by the distance fallen.

Friction work = M g H - (1/2) M V^2
where V is the final velocity of 8.00 m/s

W = 0.147)[9.81*12 - 8^2/2] = 12.6 Joules

F(average) = 12.6J/12 m = 1.05 N

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