Illustrated in Figure P4.47 is a mechanism designed to lift a platform from a lower position shown to the upper position (dashed). Two bars of length l are pinned, at points C, D and A, B, respectively. A hydraulic cylinder has pinned connections to points E and F. Shortening the hydraulic cylinder's length causes the two bars to pivot and move the platform from the bottom position to the top position. Tasks:
(a) Select coordinates and draw the assembly in a general position. Show your coordinates on the figure. State the general geometric relationships between your variables.
(b) For a general position, assume that the hydraulic cylinder is getting shorter at the constant rate v0.
(c) Derive general expressions for the angular velocities of links AB and EF. Put your equations for the unknown angular velocity terms in matrix equation format for solution.
(d) Derive general expressions for the angular accelerations of links AB and EF. Put your equations for the unknown angularacceleration terms in matrix equation format for solution.
(e) Derive general expressions for the vertical velocity and acceleration of the platform.
