What is the tangential acceleration of a flywheel particle during deceleration?

[RaoulDuke]

Homework Statement

The flywheel of a steam engine runs with a constant angular speed of 375 rev/min. When steam is shut off, the friction of the bearings stops the wheel in 1.8 h.

At the instant the flywheel is turning at 75 rev/min, what is the tangential component of the linear acceleration of a flywheel particle that is 50 cm from the axis of rotation?

Angular Acceleration: -3.47 rev/(min^2)

Homework Equations

Tangential component of the linear acceleration = (angular acceleration)(radius to object)

The Attempt at a Solution

I tried dividing the angular acceleration figure by 60 to make it in rev/(sec^2), then multiplied by r (.5 m), and ended up with the wrong answer. I tried multiplying that angular acceleration figure by 2pi to convert it to radians then multiplied it out, but still no dice. I have one attempt left. Do I need to clarify anything?

 

[rock.freak667]

The units are rev/min². 1 revolution is 2π rad and 1min² is 3600s², so you need to multiply rev/min² by 2π/3600 to get it into rad/s²

 

[RaoulDuke]

ah, so I was close. thanks.