Question

A force of 200 N is exerted on a snack box of 5 kg still on the floor. If the coefficient of friction is 0.3, calculate the static friction.

Answer 1

Given:

A force of 200 N is exerted on a snack box of 5 kg still on the floor.

To find:

Static friction?

Calculation:

First calculate the maximum limiting friction that can keep the box at rest :

$f_{max}=\mu_{s}N$

$\implies f_{max}=\mu_{s}(mg)$

$\implies f_{max} = 0.3 \times (5 \times 10)$

$\implies f_{max} = 15 \: N$

Now, force of 200 N > $f_{max}$, that means the box has started moving (kinetic friction is getting applied).

So, the net friction now getting applied is : $\boxed{f_{k}=\mu_{k}N}$ , $\mu_{k}$ is the dynamic coefficient of friction.

Hope It Helps.