You are bending your upper body forward, while your legs remain perfectly straight and their center of gravity remains over the back of your feet (see cartoon below). What is the maximum angle  you can lean forward by without tipping over?

Question

Assume that your upper body represents 65 % of your total body weight W and your legs comprise the remainder. Assume further that the center of gravity for your legs is 0.6 m above the ground while the center of gravity for the upper body is 0.4 m above the hip joint. The tip of your toes is 20 cm in front of the point over which your leg weight rests.

Answer 1

Edit: That box is a theta symbol.