Question

The diagram shown the $CD$ rotating clockwise (as seen from above) in the $CD$-player. After turning it off , the $CD$ shows down. Assuming it has not come to a stop yet, the direction of the acceleration of point $P$ at this instance is

• A. $\downarrow$
• B. $\nearrow$
• C. $\to$
• D. $\searrow$

Answer 1

The correct option is D $\searrow$

Direction of tangential acceleration:
When speed is increasing then ${\alpha }_t\text{and}v$ are parallel and vice versa.
Net acceleration as shown in figure

Hence centripetal acceleration is towords centre and as speed is decreasing therefore direction of tangential acceleration is opposite to instantaneous velocity.

Final Answer: (a)