A 20.0-kg rock is sliding on a rough, horizontal surface at 8.00 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?

Therefore,

The average power produced by friction as the rock stops is 156.86 Watts.

Explanation:

Given:

mass = m =20.0 kg

initial velocity,

coefficient of kinetic friction,

To Find:

average power, P =?

Solution:

According to Newton's Second Law,

Also Friction force,

Therefore,

Substituting the values we get

Since Rock is getting stopped therefore acceleration is negative.

Final velocity will also be ZERO.

Now by Kinematic Equation

Substituting the values we will get time 't',

Now  according to work theorem ,

which is equal to

Substituting the values we get

Now ,

Substituting the values we get

Therefore,

The average power produced by friction as the rock stops is 156.86 Watts.

measuring things 1 litre of water