Flywheels are typically made of steel and rotate on conventional bearings; these are generally limited to a revolution rate of a few thousand RPM. Some modern flywheels are made of carbon fiber materials and employ magnetic bearings, enabling them to revolve at speeds up to 60,000 RPM (1 kHz). Carbon-composite flywheel batteries have recently been manufactured and are proving to be viable in real-world tests on mainstream cars.
1925: The Tri-State Tornado. Indiana was one of three Midwest states in the path of the deadliest tornado in American history. On March 18, 1925, the Tri-State Tornado traveled a record 219 miles on the ground from Missouri through Illinois and into Indiana, where it struck Posey, Gibson and Pike counties.
What at one time was thought to be the record holder for the longest tornado path is now thought to be the longest tornado family, with a track of at least 293 miles (472 km) on May 26, 1917 from the Missouri border across Illinois into Indiana.he Tri-State Tornado of March 18, 1925 killed 695 people in Missouri (11), Illinois (613), and Indiana (71). The outbreak it occurred with was also the deadliest known tornado outbreak, with a combined death toll of 747 across the Mississippi River Valley.