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A body of mass m moves with the velocity v on a surface whose friction co-efficient is x . If the

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## Answers

### This Is a Certified Answer

from the laws of motion: 2 a s = v² - u²

=>
v² = - 2 a s as initial velocity = v and final is 0.

friction force = f = m a = - x m g

=> a = - x g substituting in the above equation for v, we get

v = √(2 x g s)

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Kinetic energy of the body = 1/2 * m * v²

Work done by friction when it stops the body = Force * distance

= (μ m g) * (- s)

work done by friction = - initial kinetic energy + final kinetic energy

- μ m g s = 0 - 1/2 m v²

hence, v² = 2 μ g s

so v = √(2μgs)