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A 20kg rock is sliding on a rough, horizontal surface at 8 m/s and eventually stops due to friction. the coefficient of kinetic friction between the rock and the surface is 0.200. what average power is produced by friction as the rock stops?

Respuesta :

ogorwyne

Answer:

156watts

Explanation:

M = 20

U = 0.200

Vo = 8.0

We are to get p

P = w/t

W = 1/2(vf²-Vo²)

The final velocity is 0

W =-1/2*20*8²

= -640J

Acceleration = -ug

= -0.200*9.8

= -1.96m/s^-2

We are to get t

t = 8/1.96

= 4.1s

P = w/t

= 640/4.1

= 156 watts

156watts is the average power that is produced by friction as the rock stops.