Passage X) A 2kg block hangs without vibrating at the bottom end of a spring with a force constant of 400 N/m. The top end of the spring is attached to the ceiling of an elevator car. The car is rising with an upward acceleration of `5m/`s^(2)` when the accleration suddenly ceases at t=0 and the car moves upward with constant speed. (g=10m/`s^(2)`)
What is the angular frequency of oscillation of the block after the acceleration ceases?

Options

A. `10sqrt(2)`rad/s
B. `20 rad/s`
C. `20sqrt(2)`rad/s
D. `32 rad/s`

Answer

A