A mass m is placed on a rough incline at an angle $\theta$ to the horizon.A force F is applied up the incline so that the mass slides up the incline.Using the compass rose,the direction of the frictional force is along
A)(a)
B)(b)
C)(c)
D)(d)
E)(e)

Question

A mass m is placed on a rough incline at an angle $\theta$ to the horizon.A force F is applied up the incline so that the mass slides up the incline.Using the compass rose,the direction of the frictional force is along 
A)(a) 
B)(b) 
C)(c) 
D)(d) 
E)(e)

Quizplus · Accepted Answer

The frictional force always acts in the opposite direction of the motion or the tendency of the motion. In this case, the force applied is up the incline, and the mass slides up the incline, so the tendency of motion is down the incline. Therefore, the direction of the frictional force is along choice (d), opposite to the direction of motion.

A Mass M Is Placed on a Rough Incline at an Angle