A block of mass 1kg attached to a spring is made to oscillate with...

The amplitude of damped oscillation with time $t$ and damping constant $b$ is given by,

$A = {A}_{0}{e}^{- bt / 2m}$

$⇒ \ln \left(\dfrac{{A}_{0}}{A}\right) = \dfrac{bt}{2m}$

$⇒ \ln 2 = \dfrac{b}{2m} \times 120$; here $t = 2min = 120s$

$⇒ \dfrac{0 . 693 \times 2 \times 1}{120} = b$

$⇒ b = 1 . 16 \times {10}^{- 2}kg{s}^{- 1}$.