MGIMS WARDHA MGIMS WARDHA Solved Paper-2015

  • question_answer
    A particle executes SHM of amplitude 4 cm and time period 2 s. Then, the time taken by it to move from positive extreme position to half the amplitude is

    A)  \[\frac{1}{3}s\]                                

    B)  \[\frac{1}{2}s\]

    C)  \[\frac{1}{4}s\]                                

    D)  \[2s\]

    Correct Answer: A

    Solution :

                    \[y=A\sin (\omega t+\phi )\]                             ..(i) At extreme position, \[y=A\] and \[t=0\] So,         \[A=A\sin (0+\phi )\] \[\Rightarrow \]                               \[\phi =\frac{\pi }{2}\] From Eq. (i),                 \[y=A\sin \left( \omega t+\frac{\pi }{2} \right)=A\cos \omega t\] At half the amplitude i.e. at \[y=\frac{A}{2}\] \[\frac{A}{2}=A\cos \omega t\] \[\Rightarrow \]               \[\omega t={{\cos }^{-1}}\left( \frac{1}{2} \right)\] \[\Rightarrow \]               \[\frac{2\pi }{T}t=\frac{\pi }{3}\] \[\Rightarrow \]               \[\frac{2}{2}t=\frac{1}{3}\]                 \[t=\frac{1}{3}s\]


You need to login to perform this action.
You will be redirected in 3 sec spinner