Question

The amplitude of a damped oscillation reduces to one third of its original value a in 20s. The amplitude of such oscillation after a period of 40s will be ……..

(a) a₀ /9 

(b) a₀ /6 

(c) a₀ /2 

(d) a₀ /27

Answer 1

(a) a₀ /9 

In the first 20s, the amplitude reduces to one-third of the original value, i.e., to a₀ /3, In the next 20s, it will reduce to one-third of the reduced value, i.e., to a₀ /9.