Question

An 84.7 kg cross country skieron snow has uk 0.131. Withhow much force must he pushto move at a constant speed?(Unit = N)Enter

Answer 1

Given:

`\begin{gathered} m=84.7\text{ kg} \\ \mu_k=0.131 \end{gathered}`

The frictional force is given as,

`f=\mu_kN`

Here, μ_k is coefficient of kinetic friction and N is normal reaction force.

The normal reaction force is given as,

`N=mg`

Here, g is the acceleration due to gravity. Therefore, the frictional force must be equal to,

`\begin{gathered} f=\mu_kmg \\ =0.131*84.7*9.8 \\ =108.74\text{ N} \end{gathered}`

So, to move the move the object the force must be greater or equal to the frictional force. Therefore, the force must be required to push the skier on snow at constant speed is 108.74 N.