question_answer

The radius of circle, the period of revolution, initial position and sense of revolution are indicated in the fig.         [NEET 5-5-2019] Y-projection of the radius vector of rotating particle P is:

A) (a)\[(y)t=3cos\left( \frac{3\pi t}{2} \right)\], where y in m

B) \[(y)t=3cos\left( \frac{\pi t}{2} \right)\], where y in m

C) \[(y)t=-3cos2\pi t\], where y in m

D) \[(y)t=4\sin \left( \frac{\pi t}{2} \right)\], where y in m

Correct Answer: B

Solution :

\[y=r\text{ }cos\theta \] \[y=3\text{ }cos\omega t\] \[y=3\text{ }cos\frac{2\pi }{4}.t\] \[y=3\text{ }cos\frac{2\pi }{2}\]