1. The force F has a magnitude of F = 20 lb and acting at point C, the coordinate direction angles of the force are α = 60°, β = 120°, γ = 45°. Determine the reaction at the fixed support O. Ans. -10 lb, 10 lb, -14.142 lb. -297.99 lb-ft, -15.15 lb-ft, 200 lb-ft. 2. Calculate the reactions at the fixed support of the cantilevered beam loaded as shown. Ans. 225 N, 189.71 N, 62.0671 N-m 3. Determine the reactions at A and E if P = 500 N. What is the maximum value P may have for static equilibrium? Neglect the weight of the structure compared with the applied loads. a) Ans. Ax =1285.5 N, Ay = 2964.1 N, Ex = 3285.5. b) P = 1732.1 N C 4. The two light pulleys are fastened together and form an integral unit. They are prevented from turning about their bearing at O by a cable wound securely around the smaller pulley and fastened to point A. Calculate the magnitude R of the force supported by the bearing O for the applied 2–kN load. Ans. R = 4.378 kN 5. The man pushes the lawn mower at a steady speed with a force P which is parallel to the incline. The mass of the mower with attached grass bag is 50 kg with mass center at G. If θ = 15o, determine the normal forces NB and Nc under each pair of wheels B and C. Neglect friction. Compare with normal forces for the conditions of θ = 0o and P = 0. Ans. NB = 214.19 N, NC = 259.6 N 6. The boom AB lies in the vertical y–z plane and is supported by a ball–and–socket support at B and by the two cables at A. Calculate the tension in each cable resulting from the 20 kN force acting in the horizontal plane and applied at the midpoint M of the boom. Neglect the weight of the boom. Ans. T1 = 32.97 kN, T2 = 22.819 kN, RBx = -3.42 kN, RBy = 4.7 kN, RBz = 46.98 kN 7. Determine the tensions TAE and TGF in the two supporting cables resulting from the 1.2–kN tension in cable CD. Assume the absence of any resisting moments on the base of the pole at O about the x– and y–axes, but not about z–axis. Use vector approach. Ans. TAE = 4.303 kN, TGF = 3.469 kN, Mz = 2.886 kN-m, Rx = -0.321 kN, Ry = -0.6414 kN, Rz = 7.697 kN.
© Copyright 2024 ExpyDoc