A 25-kg cover for a roof opening is maintained in a horizontal position by the brace CE. The roof forms an angle of 30o with the horizontal. The cover is 0.6 m x 0.9 m and neglect the thickness. The size of the hole in the roof is the same as the cover (the 0.9 m is the dimension for both the cover in the y-direction and the hole along the roof slope). Knowing those two sides (the cover in the y-direction and the hole along the roof), you can find the length and angle of CE (use Laws of Cosines and Sines).
Points C and E will have the same x coordinate
Determine the reactions of the brace and hinge(s) for the following two cases:
a. The cover is hinged at corners A and B as shown. Assume that hinge A does not exert a reaction in the x-direction.
b. The cover is supported by only one hinge located halfway between A and B (the two hinges at A and B are replaced with a single hinge). Neglect the width of the hinge.
** The coordinates for C, D, and E will be the same for both parts a) and b). However, do not automatically assume that any forces (except the weight of the cover) will be the same in parts a) and b). Solve for all unknowns again in part b).