A tired worker pushes a heavy (100-kg)crate that is resting on a thick pile carpet.The coefficients of static and kinetic friction are 0.6 and 0.4,respectively.The worker pushes with a force of 500 N.The frictional force exerted by the surface is
A)1000 N
B)600 N
C)500 N
D)400 N
E)100 N

Question

Quizplus · Accepted Answer

The frictional force is equal to the coefficient of friction times the normal force. The normal force is equal to the weight of the crate, which is 100 kg * 9.8 m/s^2 = 980 N. Therefore, the frictional force is 0.4 * 980 N = 392 N.

A Tired Worker Pushes a Heavy (100-Kg)crate That Is Resting