Homework 4 Method of Joints 60 pts Total 1. (27 pts) Using the Method of Joints, determine the force in each member of the truss shown below. Summarize your results in a Force Summation Diagram and in the table below the truss Support reactions are given Ay 4 4 A b E 50# - A = 200lb() A = 150 16 (1) Fx - 200 lb ( ) Member Force (lb) Tension or Compression AB (pus) CB (3pts) M

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

Aflywheel accelerates for 5 seconds at 2 rad/s2 from a speed of 20 rpm. determine the total number of revolutions of the flywheel during the period of its acceleration. a.5.65 b.8.43 c. 723 d.6.86

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false