Archeologists discovered ruins of an ancient grain silo, used for storing wheat. Assume that wheat has a density of 500 kg/m³ and can be treated as a liquid. A rectangular trap door at the bottom of the silo, with a height of 0.3 m and a width of 0.2 m, had a horizontal hinge at its top and was kept closed by a rock with a mass of 50 kg. The static friction coefficient between the rock and the ground is 0.8. Estimate the maximum height, h, of wheat that could be stored in the silo.

Contributed by Stavros Tavoularis, Department of Mechanical Engineering, University of Ottawa, Ottawa, Canada.