22-15. A platform, having an unknown mass, is supported by four springs, each having the same stiffness k. When nothing is on the platform, the period of vertical vibration is measured as 2.35 s; whereas if a 3-kg block is supported on the platform, the period of vertical vibration is 5.23 s. Determine the mass of a block placed on the (empty) platform which causes the platform to vibrate vertically with a period of 5.62 s. What is the stiffness k of each of the springs?

If both springs are usntretched when the mass is in the central position shown, determine the static deflection of the mass. What is the period of oscillatory motion about the position of static equilibrium? The mass m = 3.4, the spring constant k = 295 N/m, and the angle theta = 31 degrees

Pease scan solution

3 m 1 m 1 m Determine the natural period of vibration of the pendulum if it is given a small displacement and released. Consider the two rods to be slender, each having a weight of 120 N/m.