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.
On average Indiana 's drought conditions can range between moderate to non-existent. Currently Indiana has not seen any severe drought conditions. One of the worst droughts recorded was in the 1930's across almost the entire United States . Indiana 's climate is affected by 6 air masses at different times of the year. About 20% of Indiana 's annual precipitation comes from regional sources. The main regional source is Lake Michigan . Excessive late-winter rainfall is the cause for the most widespread floods in Indiana.