Q. The displacement y of a particle is given by$y = 4\cos^{- 4}{\left( \frac{t}{2} \right)\sin(1000t)}$. This expression may be considered to be a result of the superposition of how many simple harmonic motions?

A) 2
B) 3
C) 4
D) 5
Explanation

(b) Given,
$y = 4\cos^{2}{\frac{t}{2}\sin(1000t)}$
$= 2\left( 1 + \cos t \right)\sin(1000t)\ \left( \because 1 + \cos{\theta = 2\cos^{2}\frac{\theta}{2}} \right)$
$= 2\sin{1000t + 2\cos{t\sin{1000t}}}$
$= 2\sin{1000t + \sin{(1001)t + \sin{(999)t}}}$
Therefore, it consists of 3 SHM’s

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.

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