Engineering Mechanics Revision Finals Exam

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Problem Sheet No. 1 1. Determine the tension in cables CA and CB. Ans. TCA = 2870 N, TCB = 3520 N. 2. The uniform bar has a mass per unit length of 60 kg/m. Determine the reactions at the supports. Ans. Ay = 3060 N, By = 2060 N. 3. The uniform angle bar with equal legs has a mass of 20 kg and is supported in the vertical plane as shown. Calculate the force FA supported by the pin at A. Ans. FA = 277 N. 4. Determine the reactions at A and E if P=500 N. What is the maximum value that P may have for static equilibrium? Neglect the weight of the structure compared with the applied loads. Ans. Ax = -1290 N, Ay = 2960 N, E x= 3290 N, P=1732 N.…show more content…
Determine the tension in chain AB when the beam is clear of the platform. Ans. T = 3.53 kN A special jig for turning large concrete pipe sections (shown dotted) consists of an 80-Mg sector mounted on a line of rollers at A and a line of rollers at B. One of the rollers at B is a gear which meshes with a ring of gear teeth on the sector so as to turn the sector about its geometric center O. When ( = 00, a counterclockwise torque of 2460 N.m must be applied to the gear at B to keep the assembly from rotating. When ( = 300, a clockwise torque 4680 N.m is required to prevent rotation. Locate the mass center G of the jig by calculating (r and (. Ans. (r = 367 mm, ( = 79.80 Figure P.S.1.17 Figure P.S.1.18 Figure P.S.1.19 Figure P.S.1.20 A 50-kg acrobat pedals her unicycle across the taut but slightly elastic cable. If the deflection at the center of the 18-m span is 75 mm, determine the tension in the cable. Neglect the effects of the weights of the cable and unicycle. Ans. T = 29.4 kN The light bracket ABC is freely hinged at A and is constrained by the fixed pin in the smooth slot at B. Calculate the magnitude R of the force supported by the pin at A under the action of the 80-N.m applied couple. Ans. R = 566 N The uniform 30-kg bar with end rollers is supported by the horizontal and vertical surfaces and by the wire AC. Calculate the tension T in the wire and the reactions against the