Question

Consider a wooden box of mass m which is sitting on the floor. The floor may be level or it may be inclined, depending on the situation below. Also, you are able to apply additional forces to the box, as described below. For each situation, what is the magnitude of the NORMAL force exerted by the floor on the box?
A zero
B < mg
C > mg
D = mg

Answer 1

you are pushing the box with a force directed 12.3 degrees below the horizontal across the level floor at constant speed

the box is on the level floor, but you are pulling up on a rope attached to the top of the box

the box is on the level floor, but you are sitting on the box

the box is sitting by itself, but the floor is inclined at 34.3 degrees

you are pushing the box (with a horizontal force) across the level floor at constant speed

the box is sitting by itself on the level floor

Answer 2

I said BACBDD but that was wrong

Answer 3

I'm pretty sure it's: BBCBDD

Answer 4

The only difference is the second one in which case I suspect the box is still in contact with the floor so there is some < mg normal force acting on it.

Answer 5

ah ok, that makes sense