Question

An optical disk drive in your computer can spin a disk up to 10,000 rpm (about 1045 rad/s). If a particular disk is spun at 646.1 rad/s while it is being read, and then is allowed to come to rest over 0.569 seconds, what is the magnitude of the average angular acceleration of the disk?

Answer 1

Answer:

Angular acceleration will be $1135.5rad/sec^2$

Explanation:

We have given initial angular speed of a particular disk $\omega _i=646.1rad/sec$

And it finally comes to rest so final angular speed $\omega _f=0rad/sec$

Time is given as t = 0.569 sec

From third equation of motion we know that

$\omega _f=\omega _i+\alpha t$

So angular acceleration $\alpha =\frac{\omega _f-\omega _i}{t}=\frac{0-646.1}{0.569}=1135.5rad/sec^2$