Answer to Question #61802 in Classical Mechanics for frank godwin

Question

Two inclined planes intersect each other so as to form an equilateral triangle when viewed in vertical plane cross section. A string runs over a smooth pulley fastened at the triangle apex to masses m1 dan m2, one on each inclined plane. Use the method of virtual work to find the coefficient of static friction if the masses are on the verge of slipping in one direction (Assume µ the same on both planes ; neglect mass and stretching of string)