A disk of radius 10 cm speeds up from rest. It turns 60 radians reaching an angular velocity of 15 rad/s. What was the angular acceleration? B. How long did it take the disk to reach this velocity?​

Tornadoes form in unusually violent thunderstorms when there is sufficient (1) instability and (2) wind shear present in the lower atmosphere. elaborate on what does instability mean when discussing the formation of a tornado? a) dry air in the middle atmosphere being rapidly cooled by rain b) winds at all levels of the atmosphere are strong and turn with height c) an isolated strong thunderstorm just ahead of a squall line that merges with the squall line d) very warm, humid conditions in the lower atmosphere; cooler than usual conditions in the upper atmosphere