Q: The place where a river meets the sea is called a(n) __________. A. estuary B. isthmus C. escarpment D. peninsula. A: Place where river meets sea is estuary. Log in to see link for more information.
Although The Guinness Book of Records recorded the XF-84H as the fastest propeller-driven aircraft ever built, with a design top speed of 670 mph (1,080 km/h) (Mach 0.9) and 623 mph (1,003 km/h) (Mach 0.83) during tests, this claim has been disputed.
Guinness World Records recognized NASA's X-43A scramjet with a new world speed record for a jet-powered aircraft - Mach 9.6, or nearly 7,000 mph. The X-43A set the new mark and broke its own world record on its third and final flight on Nov. 16, 2004. In March 2004, the X-43A set the previous record of Mach 6.8 (nearly 5,000 mph). The fastest air-breathing, manned vehicle, the U.S. Air Force SR-71, achieved slightly more than Mach 3.2. The X-43A more than doubled, then tripled, the top speed of the jet-powered SR-71.