Calculating angular velocity and acceleration of planet Io?

Angular velocity about polar axis of Io:

w = 2π/T = 2π/35400 = 1.77491E-4 rad/sec

α = dw/dt = -1.77491E-4/(10*365*24*3600) = -5.6282E-13 rad/sec²

The orbital angular velocity Ω = 2π/1022976 = 6.142E-6 rad/sec, which when added to w gives w' = 1.836E-4 rad/sec (the w as seen from a great distance). This increases the value of α by a factor of 1.0346. [All this assumes the orbital and rotational angular velocity have the same sign}

For gi, I had to look up the mass of Io, m = 8.9319E22 kg:

then,

gi = G*m/R² = 6.67E-11*8.9319E22/(182100)²

gi = 1.7966 m/sec²

This is about what I remember from the last time I was there......