I was listening an undisclosed vinyl record when I was inspired to write this question. I changed the record player's speed (angular speed) setting...

I was listening an undisclosed vinyl record when I was inspired to write this question. I changed the record player's speed (angular speed) setting from 45 rpm to 33.3 rpm. let us approximate the angular acceleration alpha as constant and 0.750 seconds in duration.

this vinyl tecord is 17 cm in diameter and rotates clockwise.

1. first consider the time interval when the record is speeding up i.e during alpha

a. calculate the angular acceleration alpha

b calculate the angular displacement delta theta for the entire 0.750 sec and how many full circles (rev) is this?