The amplitude \( A(t) \) of a damped oscillator is given by: \[ A(t) = A_0 e^{-\gamma t} \] Where:
After 2 seconds, it's given: \[ A(2) = \frac{1}{e} A_0 = A_0 e^{-2\gamma} \] Divide both sides by \( A_0 \): \[ \frac{1}{e} = e^{-2\gamma} \] Take natural log on both sides: \[ -1 = -2\gamma \quad \Rightarrow \quad \gamma = \frac{1}{2} \]
\[ A(4) = A_0 e^{-\gamma \cdot 4} = A_0 e^{-4 \cdot \frac{1}{2}} = A_0 e^{-2} \] \[ A(4) = \frac{1}{e^2} A_0 \]
The amplitude of the oscillator after 4 seconds is: \[ \boxed{\frac{1}{e^2} A_0} \]
A particle is executing simple harmonic motion with a time period of 3 s. At a position where the displacement of the particle is 60% of its amplitude, the ratio of the kinetic and potential energies of the particle is: