A massless length of twine can withstand a maximum tension of 490 N. The twine is used to spin a 28-kg ball in horizontal circular motion of radius 1.8 m. The ball is spun faster and faster until the twine breaks. What was the maximum speed of the ball?
 7.2 m/s
 3.2 m/s
 5.6 m/s
 11 m/s