Question

A box is being pulled to the right. The free body diagram is shown. What is the magnitude of the kinetic frictional force?
 25 N
125 N
375 N
500 N

Answer 1

25N
this is because the kinetic frictional force would be the force opposing the kinetic force to the right
Hope this helps!

Answer 2

The correct answer is 25 N.

A box is pulled to the right and the forces are as shown in the free-body diagram. The applied force which pulls the body is 125 N and is shown on the right hand side of the box.  The kinetic friction force has to be in the negative x direction. This is because friction is always in the direction opposite to the motion. The only force in the direction of the negative x-axis is 25 N.

The correct answer is 25 N