# Forces in equilibrium

1. Dec 11, 2005

### Greenrose

Hi im struggling with this physics question can u help please
2 friends are carrying a 200kg crate up a flight of stairs. The crate i 1.25m long and 0.50m high and its center of gravity is at its center. The stairs make a 45 degree angle with respect to the floor. The crate is also at a 45 degree angle so the bottom side of crate is parallel to the slpoe of stairs. If the force of each person is vertical, what is the magnitude of each force?

2. Dec 11, 2005

### Staff: Mentor

The center of mass is at the center, however, when the crate is rotated 45°, the rotation of the crate shifts the CM over the person on the back edge.

On a level ground, assuming CM was in the center, then both people would support half the weight.

Draw a picture of a rectangle rotated 45° and determined how much of the area is to the either side of the lower corner, and how that area relates to the shift in CM.

Both people still must support the 200 kg (1960 N), but one will support more than the other.