# Homework Help: A couple of angular accelaration problems

1. Nov 14, 2005

### backseatgunner

I'm having many a woes with angular accelaration in my DE Physics class. Could you guys explain to me how to do these 3 problems. (If I can get one of them by logical deduction from the other problems dont go out of your way.) Thanks.

A merry-go-round accelerating uniformly from rest achieves its operating speed of 2.5rpm in five revolutions. What is the magnitude of its angular accelaration?

A 33 1/3-rpm record on a turntable uniformly reaches its operating speed in 2.45s once the record player is turned on. (a) What is the angular distance traveled during this time? (b) What is the corresponding arc length in feet on the circumfrence of a 12in. diamater record?

A bicycle being repaired is turned upside down, and one wheel is rotated at a rate of 60 rpm. If the wheel slows uniformly to a stop in 15s, how many revolutions does it take during this time?

2. Nov 15, 2005

### Päällikkö

You haven't showed what you've tried.

$$\theta = \theta _0 + \omega t + \frac{1}{2}\alpha t^2$$