# Angular physics with a pulley

mike.yeagley2
The question I am given is as follows:

A string is wrapped around a pulley of radius 3.25cm, and a weight hangs from the other end. The weight falls with a constant acceleration 3.10m/s^2.

1. What's the angular acceleration of the pulley?
2. If the weight starts from rest 1.55m above the floor, what's the pulley's angular velocity when the weight hits the floor?

My issue is with the equations I have available to me.

Equations: Angular Acceleration=Δω/Δt Angular Velocity=Δθ/Δt w=2pi/t and the equivalent translational versions for the weight in question 2.

I am looking to understand how to formulate the correct equations to get the answer. Any help would be appreciated.

## Answers and Replies

dauto
Is that homework?

mike.yeagley2
Yes it is. I found the equation I needed for Part one with linear acceleration, and that makes sense. The answer was 95.4rad/s^2, but the answer was the same for the second question as well, and I don't fully understand that. I am looking to understand why it is the same answer.