Physics Homework. NEED HELP!!?

Question

From the illustration below determine the normal force the floor projects to the bottom crate, given that m1=22.2kg, m2=33.5kg, m3=176kg.

This illustration shows a single pulley system with one string. Mass 2 is sitting on top of Mass3. These two masses are sitting on the floor. Mass1 is suspended in the air on the other side of the pulley.

Answer 1

M1 is pulling down on the rope (and up on the objects on the floor with a force of
F1 = ma = 22.2*9.8=217.56 N

Just sitting on the floor, M2 and M3 would have a resting force of
F2,3 = ma = (33.5+176)*9.8 = 2053.1 N

BUT... M1 is effectively pulling up on M2 and M3 with a Force of 217.56 N

Therefore, M2 and M3 are sitting on the floor with a force of
Resultant Force = F2,3 - F1 = 2053.1-217.6 = 1835.5 N (the floor pushes back with an equal and opposite force.)

Answer 2

The normal force is equal to the force that mass 2 and 3 exert on the floor. (M2+ M3- M1)*g=normal force. Mass 1 is subtracted because the pulley causes the force to be pulling up on the other two masses.

(33.5 + 176 - 22.2) * 9.81=1837.4 N

Answer 3

I am assuming that Mass3 is connected to Mass2 and that they are both connected over a pulley to Mass1.

If you look at the masses then you would add Mass3 and Mass2 together as one unit and they have a downward force into the floor. Mass1 would be applying a force through the string to lift up away from the floor.

The net force then would be the force of (Mass3 + Mass2 - Mass1)(g)

F = (176 + 33.5 - 22.2 )(g)