30kg 80ms k=100n/m $\huge \begin{align} x(t) &= A_{0} e^{- \frac{b}{2m}t }\cos\pa{\omega' t+\phi} + B\\ \omega' &=\sqrt{ \omega_{0}^2- \pa{\frac{b}{2m}}^2 } \end{align} $ $\huge \begin{align} -kx &= -b\vec v \\ -k 0.22 &= -b \vec v \\ b =100 \cdot \frac{0.22}{80} =0.275 \\ \end{align} $ $\huge \omega_{0} = \sqrt{ \frac{k}{m} } \\ $ $ \omega' = \sqrt{ \frac{k}{m} - \left( \frac{b}{2m} \right)^{2} } $ $\huge \sqrt{ \frac{100}{30} - \left( \frac{0.25}{60} \right)^{2} } = 1.83 $