Revisit Example 8.5 on p. 608 and replace the two springs with a system of two counterweig...

Revisit Example 8.5 on p. 608 and replace the two springs with a system of two counterweights P (only one counterweight is shown) each of weight Wp. Recalling that the door’s weight is W = 800 lb and that the total height of the door is H = 30 ft, if the door is released from rest in the fully open position and friction is negligible, determine the minimum value of WP so that A will strike the left end of the horizontal guide with a speed no greater than 0.5 ft/s.

Figure P8.36