A certain box is at rest on the floor while a rope is pulling to the right on the box with a force of 38 N and a rubber band is pulling to the left on the box with a force of 78 N.

Question

If the rubber band breaks, then the friction force on the box will:
(select all correct answers below)

- be static friction
- be kinetic friction
- decrease in magnitude
- increase in magnitude
- change direction

would the object change in direction and decrease in magntidue? I know the friction woukdn't become kinetic friction, but will it be static friction? physics confuses me please help. thank you.

Answer 1

the net force from the rope and rubber band is 40 N to the left ... (78 - 38)

if the rubber band breaks, the net force becomes 38 N to the right

the frictional force was 40 N, so the new 38 N resultant won't move the box

frictional force is still static
... it decreases in magnitude
... it changes direction