A 1.3-lb sphere A is dropped from a height of 1.8 ft onto 2.6-lb plate B, which is supported by a nested set of springs and is initially at rest. Knowing that the set of springs is equivalent to a single spring of constant k = 5 lb/in., determine the value of the coefficient of restitution between the sphere and the plate for which the height h reached by the sphere after rebound is maximum, the corresponding value of h, and the corresponding value of the maximum deflection of the plate.

Two steel balls, each of mass m = 1.84 kg, are welded to a light rod of length L = 545 mm and negligible mass and are initially at rest on a smooth horizontal surface. The distance b= 111 mm. A horizontal force of magnitude F= 27 N is suddenly applied to the rod as shown. Determine (a) the magnitude of the instantaneous acceleration a of the mass center G and (b) the magnitude of the corresponding rate 0 at which the angular velocity of the assembly about G is changing with time. m Answers: a = O = IN 7. 77 M m/s² rad/s²

applied mechanics 2

A 500-kg spacecraft first is placed into a circular orbit about the earth at an altitude of 4500 km and then is transferred to a circular orbit about the moon. Knowing that the mass of the moon is 0.01230 times the mass of the earth and that the radius of the moon is 1737 km, determine (a) the gravitational force exerted on the spacecraft as it was orbiting the earth, (b) the required radius of the orbit of the spacecraft about the moon if the periodic times (the periodic time of a satellite is the time it requires to complete one full revolution about the planet) of the two orbits are to be equal, (c) the acceleration of gravity at the surface of the moon.