Question

A string is being pulled with a force of 20 N and moves a 5 kg block to the left at a constant speed. What is the coefficient of friction for between the floor and the block? Enter your answer as a decimal value (Example: 0.72) * I think the answer is 20 but this question is starting frustrating me

Answer 1

μ = 0.4

Step-by-step explanation:

As, the object is moving at a constant speed. Therefore, the unbalanced force on it must be equal to zero. So, the frictional force on the object must be equal to the force applied to it:

F = frictional force

F = μR = μW = μmg

where,

F = Applied Force = 20 N

μ = coefficient of friction between wall and floor = ?

m = mass of block = 5 kg

g = 9.8 m/s²

Therefore,

20 N = μ(5 kg)(9.8 m/s²)

μ = 20 N/49 N

μ = 0.4