Question
Physics Question on Oscillations
If the ratio of the mechanical energy of a mass whose oscillations are damped to that of its free oscillations is e−3t/m , then the ratio of the amplitudes of the damped oscillations to that of free oscillations is
A
e−m3t
B
e−2m3t
C
e−m6t
D
e−2m3t
Answer
e−2m3t
Explanation
Solution
If E and E0 represent the mechanical energy of the damped and free oscillations respectively, then as per question
E0E=e−3t/m
As mechanical energy ∝(amplitude)2
∴ The ratio of the amplitudes of the damped oscillations to that of free oscillations is
A0A=(E0E)1/2
=(e−3t/m)1/2
=e−3t/2m