PDD 325 Fall 2017 Test Please place all your work and answer

PDD 325 Fall 2017 Test Please place all your work and answers to be graded on separate paper. Show all your work for maximum credit. Circle your final answers and write on one side of the page . Compute the reaction at each support for the beam below. (10 points) 1000 kN 500 kN 1000k/m 70 5 m 5 m 5 m 10 m 2. Calculate the force in the cable BC and the reaction at the pinned support at point A for the frame shown below. Neglect the weight of the beam. (15) 30 40 1000 lb 15 ft

Solution

2) T = tension

W = weight = 1000 x 0.45359 x 9.8 = 4445.2 N

L = 15 ft

TLcos(90 - 50 - 30) = 4445.2 x Lsin40

=> Tcos10 = 4445.2sin40

=> T = 2901.4 N

to find reaction at A, balance forces

=> R = - (W(-j) + Tsin30 j^ - Tcos30 i^)

=> R = Tcos30 i^ + (W - Tsin30) j^

=> R = 2512.69 i^ + 2994.5 j^

=> R = sqrt(2512.69² + 2994.5²) = 3909.05 N