Question

what is the magnitude of force of friction between the wood and a nail if the 100 J energy is required to penetrate the nail by 4cm?

Answer 1

Given:

100 J energy is required to penetrate the nail by 4cm.

To find:

Frictional force ?

Diagram:

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Calculation:

Work done by the operator can be calculated as the product of the applied force (equal to frictional force in critical cases) and the displacement.

Let applied force be F and frictional force be f :

$\sf \therefore \: W = F \times d$

$\sf \implies \: W = f \times d$

Putting the values in SI UNIT :

$\sf \implies\: 100 = f\times \dfrac{4}{100}$

$\sf \implies\: f = \dfrac{100 \times 100}{4}$

$\sf \implies\: f = 100 \times 25$

$\sf \implies\: f = 2500 \: N$

So, the frictional force is 2500 N.