Question

A simple harmonic motion is given by the equation
$x=3sin3\pi t+4cos3\pi t$
where x is in metres. The amplitude of the motion is

• A. 3 m
• B. 4 m
• C. 5 m
• D. 7 m

Answer 1

The correct option is C 5 m

Amplitude if motion represented by $x=asin\omega t+bcos\omega tisA={(a^2+b^2)}^{1/2}.HenceA={(3^2+4^2)}^{1/2}={(9+16)}^{1/2}=5m$
Therefore, the correct choice is (c).