An overhead fold-up door with height H = 30 ft consists of two identical sections hinged a...

An overhead fold-up door with height H = 30 ft consists of two identical sections hinged at C. The roller at A moves along a horizontal guide, whereas the rollers at B and D, which are the midpoints of sections AC and CE, move along a vertical guide. The door’s operation is assisted by a counterweight P. Express your answers using the component system shown.

Figure P6.131

If at the instant shown, the angle θ = 55° and P is moving upward with a speed υP = 15 ft/s, determine the velocity of point E as well as the angular velocities of sections AC and CE.