Question

A sled is sliding across the snow at $5m/s$ and stops in $5m$ with a constant rate of acceleration.
What is the coefficient of sliding friction between the sled and snow?

• A. $0.05$
• B. $0.25$
• C. $0.1$
• D. $0.35$
• E. $0.5$

Answer 1

The correct option is B $0.25$

Given : $S=5$ m $u=5$ m/s $v=0$ m/s

Using $v^2-u^2=2aS$

$\therefore$ $0-5^2=2a\times 5$ $⟹a=-2.5$ $m/s^2$

Magnitude of friction force acting on sled $f=\mu mg$

$\therefore$ $m|a|=f=\mu mg$

$⟹\mu =\frac{|a|}{g}=\frac{2.5}{10}=0.25$