Angular Acceleration problem

BrainMan

1. 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?

2. Homework Equations
ω = ωo + $\alpha$t

3. The Attempt at a Solution
I first converted 45 to radians by multiplying it by pi
45(3.14152654)/180 = .79 rad
then I plugged it into the above equation
.79 = α(1.5)
α = .53 r/s2
The actual answer is pi r/s2

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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?

BrainMan

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
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
45(3.14152654)/180 = .79 rad
That is how you convert 45 DEGREES into radians. But the number 45 has units of REVOLUTIONS, not degrees.

"Angular Acceleration problem"

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