The extremities of a 4-ft rod weighing 125 lbf can move freely and with no friction along two straight tracks. The rod is released with no velocity from the position shown. Determine: a) the angular acceleration of the rod, and b) the reactions at A and B. DO NOT ROUND OFF IN THE SOLUTION. ROUND OFF ONLY IN 2 DECIMAL PLACE IN THE FINAL ANSWER

4. A 10-kg cylinder is suspended by the frictionless and massless spring-pulley system in Figure 4 (the ring that connects the springs has negligible mass). Each spring has a rest (unstretched) length of 1 m. Find the set of spring stiffnesses KAD, KAB, and KAC that keeps this 10-kg cylinder in static equilibrium. KAD 2 m 2 m A KAB KAC 3 m- B C 4 m 3 m Figure 4 A spring-pulley system holding a cylinder in static equilibrium.

The particle of mass m = 2.3 kg is attached to the end of the light rigid bar of length L = 0.83 m. The system is released from rest while in the horizontal position shown, at which the torsional spring is undeflected. The bar is then observed to rotate 45° before stopping momentarily, (a) Determine the value of the torsional spring constant kr. (b) For this value of kr, determine the speed vof the particle when e = 25°. kT Part 1 Position 1 is the horizontal orientation shown in the figure. Position 2 is the orientation when e- 45. Find the kinetic energy in positions 1 and 2. Answers: T1- kg m²/s2 T2- kg m²/s? Answers: (a) ky = i Nem/rad (b) m/s

3. Use the three equations of equilibrium to determine the reactions at points A and D. Determine the reactions at point A and D. Show your calculation steps. 30 lo00# E F 500 #