Easy INTEGER +4 / -1 PYQ · JEE Mains 2021

Two simple harmonic motion, are represented by the equations ${y_1} = 10\sin \left( {3\pi t + {\pi \over 3}} \right)$ ${y_2} = 5(\sin 3\pi t + \sqrt 3 \cos 3\pi t)$ Ratio of amplitude of y1 to y2 = x : 1. The value of x is ______________.

Answer (integer) 1

Solution

${y_1} = 10\sin \left( {3\pi t + {\pi \over 3}} \right)$ $\Rightarrow$ Amplitude = 10<br><br>${y_2} = 5(\sin 3\pi t + \sqrt 3 \cos 3\pi t)$<br><br>$${y_2} = 10\left( {{1 \over 2}\sin 3\pi t + {{\sqrt 3 } \over 2}\cos 3\pi t} \right)$$<br><br>$${y_2} = 10\left( {\cos {\pi \over 3}\sin 3\pi t + \sin {\pi \over 3}\cos 3\pi t} \right)$$<br><br>${y_2} = 10\left( {3\pi t + {\pi \over 3}} \right)$ $\Rightarrow$ Amplitude = 10<br><br>So ratio of amplitudes = ${{10} \over {10}}$ = 1

About this question

Subject: Physics · Chapter: Oscillations · Topic: Simple Harmonic Motion

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