Friction – Page 2 – Rankers Physics
← Back to Laws of Motion

Friction

Question 1:

A body of mass m is kept on a rough horizontal surface (coefficient of friction = μ). A horizontal force is applied on the body, but it does not move. The resultant of normal reaction and the frictional force acting on the object is given by F, where F is:

F = mg
F = μmg
F = mg + μmg
F ≤ mg(1 + μ2) 1/2
View Solution

Solution:

The forces acting on the body are: Normal reaction (N=mg) (upward) and Friction force f≤μmg (opposing applied force)

The resultant force is:

F=N2+f2=mg2+(μmg)2=mg1+μ2F = \sqrt{N^2 + f^2} = \sqrt{mg^2 + (\mu mg)^2} = mg \sqrt{1 + \mu^2}

F \leq mg(1 + \mu^2)^{1/2}

Discuss this question