Angular acceleration of machinery

[Lance WIlliam]

A piece of machinery is spinning at 760rpm . When a brake is applied, its rotation rate drops to 480rpm while it turns through 210 revolutions.


What is the magnitude of the angular deceleration?

Answer in Rad/s^2

Eqn I used:$$\omega$$^2=$$\omega$$_0_^2+2$$\alpha$$(change in theta)

I put 480^2=760^2+2(alpha)210



I got 3.79e-3...
Wrong...:(
what did I do wrong? Ithink its the units, they are very confusing.

 

[cryptoguy]

i'd convert the distance to radians, and all the speeds to radians per sec right off the bat. so 760 rpm x 2pi / 60 would give you rad/s for example

 

[Lance WIlliam]

Thankyou