Question

What is coefficient of friction for a pulling a load of 400 kg by a force 40 lg

Answer 1

400 ÷ 40= 10 the quotatent is 10

Answer 2

To find:

What is coefficient of friction for a pulling a load of 400 kg by a force 40 kgf?

Calculation:

Let the coefficient of static friction between the block and the the surface be $\mu_{s}$:

Now, the net frictional force at limiting conditions:

$\therefore \: f = \mu_{s} \times N$

$\implies\: f = \mu_{s} \times (mg)$

$\implies\: f = \mu_{s} \times (400 \times 10)$

$\implies\: f = \mu_{s} \times 4000$

Now, the question says that the 40 kgf force is just enough to move the body:

$\therefore \: f = F_{applied}$

$\implies\: f =40g$

$\implies\: \mu_{s} \times 4000 = 40 \times 10$

$\implies\: \mu_{s} = \dfrac{400}{4000}$

$\implies\: \mu_{s} = 0.1$

So, coefficient of static friction between block and surface is 0.1 .