Final answer:
The statement is true; tornadoes are rotating columns of air that emerge from severe thunderstorms and can have wind speeds up to 500 km/h.
Step-by-step explanation:
The statement 'A tornado is a violently rotating column of air that may or may not be in contact with the ground' is true. Tornadoes are indeed violently rotating columns of air associated with severe thunderstorms, particularly supercells. These rotational motions originate from a rotating air column around a horizontal axis and, when conditions are right, shift into a vertical rotation that can lead to the formation of a tornado.
These powerful phenomena can produce wind speeds as high as 500 km/h (approximately 300 miles/h), especially where the funnel narrows at the bottom. The intense rotational motion is due to conservation of angular momentum, much like how an ice skater spins faster when pulling her limbs in toward her body. A key to predicting tornadoes involves analyzing atmospheric rotation, which can be carried out by meteorologists looking at vector changes and wind speeds.