Question

A body is rolling on the ground with a velocity of $1m/s$. After travelling a distance of $5m$, the body stops. The coefficient of friction is:

• A. $0.00102$
• B. $0.01$
• C. $0.102$
• D. $1.02$

Answer 1

The correct option is B $0.01$

Given that,

Initial velocity $u=1m/s$

Final velocity $v=0$

Distance $D=5m$

Now, from equation of motion

$v^2=u^2+2as$

$0=1+2\times a\times 5$

$a=-\frac{1}{10}m/s^2$

Negative sign show that the velocity is decreasing due to the opposite force

Now, friction force is

$F=\mu mg$

$ma=\mu mg$

$\mu =\frac{a}{g}$

$\mu =\frac{1}{100}$

$\mu =0.01$

Hence, the coefficient of friction is $0.01$