An optical disk drive in your computer can spin a disk up to 10,000 rpm (about 1045 rad/s1045 rad/s ). if a particular disk is spun at 910.0 rad/s910.0 rad/s while it is being read, and then is allowed to come to rest over 0.167 seconds0.167 seconds , what is the magnitude of the average angular acceleration of the disk?

To solve this problem we must keep in mind the concepts related to angular kinematic equations. For which the angular velocity is defined as

Where

Final angular velocity

Initial angular velocity

Angular acceleration

t= time

In this case we do not have a final angular velocity, then

Re-arrange for

Therefore the mangitude of the angular aceleration is 5449.1rad/s²

it is called kinetic energy

see earlier