EM 306s (12040) Statics and Dynamics Midterm Exam Feb. 20, 1989 Name: * * * * . . .. . . Time: 55 minutes Closed book, closed notes Show dl your work in a step by step fashion and follow the format as specified for the homework. If you have no time to complete all the cornputations, write down the procedure to do it. I. The two forces acting on the handles of the pipe wrenches constitute a coupIe M . Express the couple as a vector. (20 points) (25 points) 2. A force P of magnitude 90 Ib. is applied to the angle AB which is supported by a frictionless pin at ID and by cable ACB. The cabIe passes over the pulley at C. Determine the tension in the cable and the reaction at D when a=3 in. I- 5 in. I 7 in. j--..:\. ------- (25 points) 3. Two forces of magnitude P act along the diagonals of the faces of a cube of side length a as shown. (a) Replace the two forces by a system consisting of a singIe force at 0 and a couple. (b) Find the vector component of the couple in the direction of the resultant force. (30 points) 4. The 23-kg pIate ABCD measures 325 by 450 mm; it is held by hinges along edge AD and the wire BE. Determine the tension in the wire.