Chapter 10, Problem 26 Your answer is incorrect. Try again.

The flywheel of a steam engine runs with a constant angular velocity of 170 rev/min. When steam is shut off, the friction of the bearings and of the air stops the wheel in 2.4 h. (a) What is the constant angular acceleration, in revolutions per minute-squared, of the wheel during the slowdown?(b) How many revolutions does the wheel make before stopping? (c) At the instant the flywheel is turning at 85.0 rev/min, what is the tangential component of the linear acceleration of a flywheel particle that is 37 cm from the axis of rotation? (d) What is the magnitude of the net linear acceleration of the particle in (c)?

pi = 3.14
wi = 170                            // revs per min
t = (2.4 * 60)                      // time in minutes

//Part A.  (Wiley says this is correct)
a = -wi/t                           // revs per minute^2

//Part B.  (Wiley says this is correct)
rev = -(wi*wi)/(2*a)

//Part C. 
w = 85                              // new revs per min
R = 0.37                            // radius in meters

at = R * a

When I get to doing this equation, I have

(meters) (revs/min*min)

so I convert revs to 2 pi rad and min² to seconds

(2 pi rad/60*60)(meters) 

Where do my radians go? Because I'm aiming for m/s² but I'm getting radian meters / s²

I have no clue about part D yet.