Question

A book of weight 20n is pressed between two hands and each hand exerts 40n force. if book just starts to slide down. coefficient of friction is?

Answer 1

Weight of book = Friction between hands and book
mg = μN
20 = μ(40 + 40)
μ = 20 / 80
μ = 0.25

Coefficient of friction is 0.25

Answer 2

Answer:

Coefficient of friction is 0.25.        

Step-by-step explanation:

Given : A book of weight 20 N is pressed between two hands and each hand exerts 40 N force. If book just starts to slide down.

To find : Coefficient of friction ?

Solution :

A book weight = 20

The frictional force is

$F_r=\mu N$

Where, $F_r=20N$ is frictional force

$\mu$ is coefficient of friction

N=40+40=80N is the normal force (two hand pressure)

Substitute the value in the formula,

$20=\mu\times 80$

$\mu=\frac{20}{80}$

$\mu=0.25$

Therefore, Coefficient of friction is 0.25.