1. The problem statement, all variables and given/known data The flywheel of a steam engine runs with a constant angular speed of 156rev/min. When the steam is shut off, the friction of the bearings and of the air brings the wheel to rest in 2.20h. What is the tangential linear acceleration of a particle 52.4cm from the axis of rotation when the flywheel is turning at 72.5rev/min. 2. Relevant equations At= r(alpha) I know what the radius is, so I must find angular acceleration. alpha = (Wf-Wi)/t _____=(0-156)/(2.2*60) _____=-1.18rev/min^2 Therefore At= (52.4cm)(-1.18rev/min^2) 3. The attempt at confusion So now that I am done, I am left wondering why someone would put 72.5 rev/min in the equation. I was tempted to put that into my equation to find alpha, but then I am lacking time. I then turned towards my linear equivalent equations, but I am lacking time it takes to decelerate to 72.5 or the amount of rotations it takes to get that far. What am i meant to do?