A block is pulled at constant speed along a rough level surface by a rope that makes an angle of 30° with respect to the horizontal. The applied force along the rope is . The force of kinetic friction between the block and the surface is 10 N.
-Which one of the following actions will increase the frictional force on the block?
A)increasing the contact surface area
B)decreasing the contact surface area
C)increasing the weight of the block
D)decreasing the speed of the block
E)increasing the angle made by the rope

Question

A block is pulled at constant speed along a rough level surface by a rope that makes an angle of 30° with respect to the horizontal. The applied force along the rope is . The force of kinetic friction between the block and the surface is 10 N. 
-Which one of the following actions will increase the frictional force on the block?
A)increasing the contact surface area 
B)decreasing the contact surface area 
C)increasing the weight of the block 
D)decreasing the speed of the block 
E)increasing the angle made by the rope

Quizplus · Accepted Answer

Increasing the weight of the block increases the normal force, which in turn increases the frictional force, as friction is proportional to the normal force.

A Block Is Pulled at Constant Speed Along a Rough