Consider the cross-section below. A compressive load P is applied at any point (ex, ey) with respect to the principal axes x and y. The moment of P about these axes are respectively
Problem 521
In Fig. P-519, if μ = 0.30 under both blocks and A weighs 400 lb, find the maximum weight of B that can be started up the incline by applying to A a rightward force P of 500 lb.
Problem 520
Referring to Fig. P-519, block A weighs 4 kN and B weighs 3 kN. If μ = 0.20 under B, compute the minimum coefficient of friction under A to prevent motion.
Problem 519
In Fig. P-519, two blocks are connected by a solid strut attached to each block with frictionless pins. If the coefficient of friction under each block is 0.25 and B weighs 2700 N, find the minimum weight of A to prevent motion.
Problem 356
The cantilever truss shown in Fig. P-356 is supported by a hinge at A and a strut BC. Determine the reactions at A and B.
Problem 257
Three bars AB, AC, and AD are pinned together as shown in Fig. P-257. Initially, the assembly is stress free. Horizontal movement of the joint at A is prevented by a short horizontal strut AE. Calculate the stress in each bar and the force in the strut AE when the assembly is used to support the load W = 10 kips. For each steel bar, A = 0.3 in.2 and E = 29 × 106 psi. For the aluminum bar, A = 0.6 in.2 and E = 10 × 106 psi.
