In this experiment, you traced three rays to determine the focal length or a mirror or lens. What was the minimum number you needed

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