Chapter 3, Problem 9P

The 19-lb weight is supported by the cord AC and roller and by a spring. If the spring has an unstretched length of 7.1 In. and the weight is in equilibrium when d = 5.5 In., determine the stiffness k of the spring. Supply the answer in lb/in. Add your answer -12 in.

A.The bar of negligible weight is supported by two springs, each having a stiffness k = 98 N/m. If the springs are originally unstretched, and the force is vertical as shown, determine the angle the bar makes with the horizontal, when the 31-N force is applied to the bar. B.Determine the stiffness k of each spring so that the 32-N force causes the bar to tip = 13.6° when the force is applied. Originally the bar is horizontal and the springs are unstretched. Neglect the weight of the bar.

The torsional spring at B is undeformed when bars OB and BD are both in the vertical position and overlap. If a force F is required to position the bars at a steady orientation θ = 64°, determine the torsional spring stiffness kT. The slot at C is smooth, and the weight of the bars is negligible. In this configuration, the pin at C is positioned at the midpoint of the slotted bar.