F = m A (Newton #2)
m = F/A
m = (12.2 N) / (265.2 m/s²)
m = (12.2 / 265.2) kg
m = 0.046 kg
(46 grams; not bad; the international standard is "not more than 45.93 grams")
Note: 265.2 m/s² = about 27 G's . Seems to me like that would rip the ball to shreds, but I don't really know anything about golf.)