Question

The time period of a particle performing S.H.M. is $\pi s.$ It starts motion from the mean position. After $\pi /6s,$ its velocity is $4cm/s.$ The amplitude is :

• A. $\pi cm$
• B. $4cm$
• C. $1cm$
• D. $3.28cm$

Answer 1

The correct option is C $1cm$

$\begin{array}{c}V=Aw\cos \left(wt+\varphi \right),given,w=\frac{2R}{R}=2,\varphi -0\\ V=A2\cos 2t=4cm/s\\ \Rightarrow A=2\cos 2\times \frac{\pi }{6}=2\cos {60}^{\circ }=1cm\end{array}$