A dentist causes the bit of a high - speed drill to accelerate from an angular speed of 1 . 2 0 x 1 0 4 rad / s to an angular speed of 5 . 4 2 times 1 0 4 rad / s . In the process, the bit turns through 2 . 0 6 x 1 0 4 rad.Assuming a constant angular acceleration, how long would it take the bit to reach its maximum speed of 7 . 7 2 x 1 0 4 rad / s , starting from rest?N
