Question

A body is projected along a rough horizontal surface with a velocity 6m/s. If the body comes to rest after travelling 9m then coefficient of sliding friction is

Answer 1

Answer:

Coefficient of sliding friction is 0.204

Explanation:

It is given that,

Initial velocity of the body, u = 6 m/s

Final velocity, v = 0 (as it comes to rest)

Distance, d = 9 m

We need to find the coefficient of sliding friction. Let it is equal to $\mu_s$. Frictional force is given by :

$F=\mu_s\times N$

$F=\mu_s\times mg$

Also, $ma=\mu_s\times mg$

$\mu_s=\dfrac{a}{g}$...............(1)

Acceleration, a can be calculated using third equation of motion as :

$a=\dfrac{v^2-u^2}{2s}$

$a=\dfrac{-(6\ m/s)^2}{2\times 9\ m}$

$a=-2\ m/s^2$

The minus sign shows that the force is acting in opposite direction of frictional force.

Equation (1) becomes,

$\mu_s=\dfrac{2}{9.8}$

$\mu_s=0.204$

So, the coefficient of sliding friction is 0.204. Hence, this is the required solution.