1. The problem statement, all variables and given/known data A refrigerator with a mass of 100kg measures 150cm high by 75 cm wide by 75 cm deep. How much force applied horizontally at the top edge of the front will make it start tipping backward? Assume that the center of mass is at the center of the refrigerator. 2. Relevant equations Moment= r x F 3. The attempt at a solution I do not know how to start this problem. I have drawn a 3D figure of the refrigerator and have ∑Fy=mg+N (vector) and ∑Fx=F+Ff (force applied+force of friction, again vector). All the previous examples I was given were the typical ladder leaning on the wall type of questions but this one has three dimensions. Any tips will be appreciated.