Physics help please!!!
posted by john .
The angular speed of digital video discs (DVDs) varies with whether the inner or outer part of the disc is being read. (CDs function in the same way.) Over a 133 min playing time, the angular speed varies from 570 rpm to 1600 rpm. Assuming it to be constant, what is the angular acceleration (in rad/s2) of such a DVD?

angular acceleration= (wfwi)/timeinseconds
change rpm to rad/sec
570rpm*2PIrad/rev*1min/60sec. 
so 570rpm*2pirad = 3581.415625
i divide that with rev*1min/60 sec == 59.69 is that correct ??