A mass m=9.0 kg is attached to a spring and allowed to hang in the earth gravitational field. The spring stret

A mass m=9.0 kg is attached to a spring and allowed to hang in the earth gravitational field. The spring stretches 3.0 cm before it reaches its equilibrium position. If allowed to oscillate, what would be its frequency ?

A.0.58 Hz
B. 2.9 Hz
C. 1.8 Hz
D. 0.33x10^-3 Hz

In equilibrium position,
mg = k * Δl
=> spring constant, k
= (mg) / (Δl)
= (9 * 9.81) / (0.03) N/m
= 2943 N/m
frequency, f
= (1/2π) √(k/m)
= (1/2π) √(2943/9)
= 2.878 Hz
Answer:- B.