Angular Acceleration: Solve 500-700rev/sec in 30sec

[Sparky500]

Homework Statement

A fan increases in speed from 500 to 700rev/sec in 30 seconds. What is the average angular acceleration during that time?

Homework Equations

The Attempt at a Solution

The answer i get for this one is

∝=(700-500 rev⁄sec)/3sec

any input appreciated

 

[malawi_glenn]

well, same problem again.

1. the angular acceleration has the units of rad/s^2
2. how many rad is 200 rev?

 

[Sparky500]

sorry i have given the wrong answer for you to look at, the correct answer (one i have) should have read:

=418.9 rad⁄s^2

 

[malawi_glenn]

200 * 2pi / 30 = 41.89 ...

 

[Sparky500]

hi, just noticed that i had a misprint in my original question above (sorry about this) in the question it says 30 secs whereas it should read 3.0 secs.
therefore would my original answer be the correct one (sorry)