Polly is pushing a box across the floor with a force of 30 n. the force of gravity is –8 n, and the normal force is 8 n. which value could describe the force of friction if polly could not move the box?

a. –30 n
b. –8 n
c. 8 n
d.30 n

The frictional force will be -30 N.
In order for the box to move, the horizontal force must be greater than the frictional force. The horizontal force applied is 30 N. The box will remain stationary if the frictional force is equal in magnitude but opposite in direction to the horizontal force.
This is also being demonstrated in the fact that vertical force due to gravity is equivalent to the normal force, meaning the box does not move vertically.

The answer is actually 30 i jus took da pre-test