Slanted surfaces with friction: A brick is resting on a rough incline as shown in the figure. The friction force acting on the brick, along the incline, is
A) zero.
B) equal to the weight of the brick.
C) greater than the weight of the brick.
D) less than the weight of the brick.

Question

Slanted surfaces with friction: A brick is resting on a rough incline as shown in the figure. The friction force acting on the brick, along the incline, is 
A) zero. 
B) equal to the weight of the brick. 
C) greater than the weight of the brick. 
D) less than the weight of the brick.

Quizplus · Accepted Answer

The friction force acting on the brick is opposing the motion of the brick down the incline. Therefore, the friction force will be less than the weight of the brick which is acting down the incline. Thus, only choice D is correct.

Slanted Surfaces with Friction: a Brick Is Resting on a Rough