A 12-kg mass is placed on a 29° incline and friction keeps it from sliding.The coefficient of static friction in this case is 0.633,and the coefficient of sliding friction is 0.524.The mass is given a shove causing it to slide down the incline.What is the frictional force while the mass is sliding?
A) 57.01 N
B) 102.86 N
C) 53.90 N
D) 65.11 N
E) 10.50 N

Question

A 12-kg mass is placed on a 29° incline and friction keeps it from sliding.The coefficient of static friction in this case is 0.633,and the coefficient of sliding friction is 0.524.The mass is given a shove causing it to slide down the incline.What is the frictional force while the mass is sliding?
A) 57.01 N
B) 102.86 N
C) 53.90 N
D) 65.11 N
E) ​10.50 N

Quizplus · Accepted Answer

The frictional force while the mass is sliding is calculated using the coefficient of sliding friction. The normal force is the component of the gravitational force perpendicular to the incline, which is $mg \cos(\theta)$. Thus, the frictional force is $ \mu_k \times mg \cos(\theta) = 0.524 \times 12 \times 9.8 \times \cos(29^\circ) \approx 53.90 \, \text{N} $.

A 12-Kg Mass Is Placed on a 29° Incline and Friction