Question

A 2.03 kg book is placed on a flat desk. Suppose the coefficient of static friction between the book and the desk is 0.542 and the coefficient of kinetic friction is 0.294. How much force is needed to begin to move the book and how much force is needed to keep the book moving at a constant velocity

Answer 1

Answer:

Force is needed to begin to move the book and  force needed to keep the book moving at a constant velocity is 10.78 N and 5.85 N.

Explanation:

Given :

Mass of book , M = 2.03 kg.

Coefficient of static friction , $\mu_s=0.542 \ .$

Coefficient of kinetic friction , $\mu_k=0.294\ .$

Force, required needed to begin to move the book ,

$F=\mu_sN=\mu_s(mg)=0.542\times 2.03\times 9.8=10.78\ N.$

Now, We know kinetic friction acts when object is in motion .

Therefore , Force, required o keep the book moving at a constant velocity

$F=\mu_kN=\mu_k(mg)=0.294\times 2.03\times 9.8=5.85\ N.$

Hence, this is the required solution.