# Angular Acceleration problem

## Homework Statement

A turntable moves from rest to an angular speed of 45 rev/min in 1.5 s. What is its average angular acceleration?

## Homework Equations

ω = ωo + $\alpha$t

## The Attempt at a Solution

I first converted 45 to radians by multiplying it by pi
then I plugged it into the above equation
.79 = α(1.5)
α = .53 r/s2
The actual answer is pi r/s2

Nathanael
Homework Helper
Your conversion is where the problem is. You want to convert from rev/min to rad/sec

First let's convert from rev/min to rad/min:

How many radians are in 1 revolution?

Your conversion is where the problem is. You want to convert from rev/min to rad/sec

First let's convert from rev/min to rad/min:

How many radians are in 1 revolution?
2 pi

Nathanael
Homework Helper
2 pi

So if I have $45\frac{rev}{min}$ how many $\frac{radians}{min}$ will it be?

Nathanael
Homework Helper
I first converted 45 to radians by multiplying it by pi