Question

You need to move a 122-kg sofa to a different location in the room. It takes a force of 81 N to start it moving. What is the coefficient of static friction between the sofa and the carpet?

Answer 1

The coefficient of static friction = 0.0677

Explanation:

Friction: These is the force that tend to oppose two bodies in contact. The force of friction is a contact force.

F = μR

Making μ the subject of the equation above.

μ = F/R ....................... Equation 1

Where F = frictional Force, R = normal reaction, μ = Coefficient of static friction

But, R = mg ................ Equation 2

Given: m= 122 kg,

Constant: g = 9.8 m/s²

Substituting these values into equation 2

R = 122×9.8

R = 1195.6 N.

Also Given: F = 81 N.

Also substituting these values into equation 1

μ = 81/1195.6

μ = 0.0677

Therefore the coefficient of static friction = 0.0677