Physics - NLM Question with Solution | TestHub

Using the first equation of motion:

$v=u+at$

Substituting the given values $u=4\text{ m/s}$, $v=0\text{ m/s}$, and $t=5\text{ s}$:

$0=4+a(5)$

$a=-0.8{\text{ m/s}}^2$

The retardation is provided by the kinetic friction. Equating the frictional force to mass times acceleration:

$\mu mg=m|a|$

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

Substituting $g=10{\text{ m/s}}^2$:

$\mu =\frac{0.8}{10}=0.08$

Answer: $0.08$