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.
Mach 1 is approximately equal to 663 mph. Airlines planes go mostly at the speed of mach 0.7. Military planes can go up to the speed of mach 5. According to the Guinness Book of records the fastest speed of an airplane recorded is 2193 miles per hour or 4520 miles per hour according to the World Book of Encyclopedia.