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AP® Physics 1 & 2

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Moderate

Work Done on Falling Object

APPH12-IWYVXM

A $5\text{ kg}$ rock is thrown directly downward off a cliff ($h = 100\text{ m}$) with an initial velocity of $25\text{ m/s}$. Just before striking the ground, the rock has a velocity of $35\text{ m/s}$.

How much work was done by frictional forces?

A

$4905\text{ J}$

B

$3063\text{ J}$

C

$3405\text{ J}$

D

$0\text{ J}$; There are no frictional forces acting on the rock.