A heavy wooden block is dragged by a force along a rough steel plate, as shown below for two possible situations. The magnitude of is the same for the two situations. The magnitude of the frictional force in (ii), as compared with that in (i) is:
A) the same
B) greater
C) less
D) less for some angles and greater for others
E) can be less or greater, depending on the magnitude of the applied force.

Question

A heavy wooden block is dragged by a force  along a rough steel plate, as shown below for two possible situations. The magnitude of  is the same for the two situations. The magnitude of the frictional force in (ii), as compared with that in (i) is: 
A) the same 
B) greater 
C) less 
D) less for some angles and greater for others 
E) can be less or greater, depending on the magnitude of the applied force.

Quizplus · Accepted Answer

In situation (ii), the angle of the applied force is steeper, meaning the force is pulling more horizontally than in situation (i). This reduces the normal force acting on the block, which in turn reduces the frictional force. Thus, the magnitude of the frictional force in (ii) is less than that in (i).

A Heavy Wooden Block Is Dragged by a Force