What are compressions in a sound wave?

A spring is attached to points A and B as shown in the figure.  The spring constant, k, is given equal to k = 100 N/m and it is stretched by s = 0.1m.  Distance b = 2 m. Consider the force which the spring exerts on point A only and calculate the moment it produces about the coordinate axes x and y.    Calculate the moment produced by the same force about axis OB. You need to show the expression using numerical values; however, you do not need to complete the calculations to find the value of the moment.

Determine the resultant force of forces F2  and F3 as a cartesian vector.  Note that the angles shown in the force F2 are the coordinate angles α, β and γ with respect to the coordinate axes. You may ignore force F1. 

The structure is supported by two pins at points A and B and a roller at point F. It is subjected to a distributed load at segment CG, two point loads and a couple moment, as shown in the figure. Calculate the support reactions at points A, B, and F and the forces at the internal pins at C and D. Show all your work including a Free Body Diagram to receive full credit.

The shaft is supported by a journal bearing at A and a thrust bearing at B. Determine the tension in cable CE and the reactions at A and B when a load P = 110 lb and a couple moment M = 40 lb·in is applied. Assume the bearings are properly aligned. For full credit, you must show these steps: Draw a free body diagram. Write sum of forces acting on the body. Take the sum of moments about point B.

A truss is supported by a pin at point F and a roller at point J. Determine the force in members AB, FG, and DG and state whether the members are in tension or compression.  Show all your work and FBD(s) to receive full points.

Find the magnitude of the resultant force of the distributed loads acting on the beam AB.  Justify your answer to receive full points.

A box of mass 100 kg rests on an inclined surface is subjected to a load P.  The coefficient of friction between the surface and the box is equal to μs = 0.40. Find the minimum force required to move the box up on the inclined surface. You must include a FBD to receive full points. Hint: Consider two cases to determine the required load for the box to move.

Find the centroid, C, of the cross-section shown in the figure and the moment of inertia about the centroidal axis x’’. Show all your calculations to receive full credit. The figure is not in scale. 

Given  α = 25◦, b = 2.13 in. and d = 2.51 in. find the moment generated by the P = 173 lb forces. Note that positive moments are counterclockwise. Justify your answer to receive full points.