Amass weighing 64 lb is attached to a spring hanging from the ceiling and comes to rest at its equilibrium position. at time tequals0, an external force of upper f (t )equals3 cosine 5 t lb is applied to the system. if the spring constant is 10 lb/ft and the damping constant is 2 lb-sec/ft, find the steady-state solution for the system. use g equals 32 ft divided by sec squared.

Amichelson interferometer operating at a 600 nm wavelength has a 3.02-cm-long glass cell in one arm. to begin, the air is pumped out of the cell and mirror m2 is adjusted to produce a bright spot at the center of the interference pattern. then a valve is opened and air is slowly admitted into the cell. the index of refraction of air at 1.00 atm pressure is 1.00028.how many bright-dark-bright fringe shifts are observed as the cell fills with air?