Question

The cart shown in Figure 3 is connected to the wall by spring kA. It weighs 20 kgf and the system parameters are given as kA-800 N/m, kB = 600 N/m, CA-2 N sec/m, and g 9.81 m/sec2. The springs kA and kB are initially unstretched, and the mass m is at rest. For 0 < 3. K ta (t,-6n), the plate at the end of the spring-damper combination has motion defined by an Xp(t) = 25t mm. After t > ta, the plate is held motionless at Xb(t)-Xb(ta) with zero velocity. Tasks: (a) Select a coordinate, draw a free-body diagram, and state the EOMs for both the two conditions of the base plate. (b) Solve for the cart's displacement as a function of time for both the conditions of the base plate. Plot the displacement. (c) Determine the cart's peak amplitude of the displacement. Massless plate CA kA Im kB Figure 3: Base Excitation System.

Answer 1