Question

A particle is executing the motion $x=a\,\cos (\omega t-\theta ).$ The velocity of the particle is:

• A. $a\omega \cos \theta$
• B. $a\omega$
• C. $a\omega \sin \theta$
• D. none of these

Answer 1

Answer: (B)

$a\omega$

Answer 2

Given equation is $x=a \cos (\omega t-\theta)$
So, velocity $\left|\frac{d x}{d t}\right|=a \omega \sin (\omega t-\theta)$
At $(\omega t-\theta)=90^{\circ}$,
the velocity will be maximum,
therefore the maximum velocity is
$v=\alpha\, \omega$