A large heavy box has its center of mass at a distance l from a bottom corner and at an altitude h above the ground. At what critical angle alpha does the box start to fall over when it is tilted? Assume that the bottom corner of the box has a large friction coefficient with the floor and does not slip?

1) arctan l/(2h)

2)arctan l/h

3)arcsin l/(2h)

4)arccos l/(2h)

Suppose now that the box has essentially all of its mass concentrated at the center of its bottom surface. What is the critical angle at which the box falls over when tilted? Again, assume there is large friction with the floor, so the box never slips.

1)0 degree
2)45 degree
3)67 degree
4)90 degree

I get arctan(l/h)

So, if h=0, that means part 2 is 90 degrees.