A slightly loosely fit window is balanced by two strings which are connected to weights `w//2` each. The strings pass over the frictionless pulleys as shown in the figure. The strings are tied almost at the corner of the window. The string on the right is cut and then the window accelerates downwards. If the coefficients of friction between the window and the side supports is `mu` then calculate the acceleration of the window in terms of `mu` , a, b and g, where a is width and b is the length of the window.

Answer

`a = [(b - mu a)/(3b + mu a)]`