Then a helicopter is flying low and u can hear the blades going through the air. Well how many rotations have been completed by the time u here one rotation?
2006-12-31 12:48:05 · 5 answers · asked by darkmagician1390 2 in Cars & Transportation ➔ Aircraft
it will depend on how many blades the helicopter has. the old huey's had 2, and you might remember the wapp wapp sound that they made. every thime that one of the blades goes through the air you hear it. so for every two that you hear is one revolotion.each helicopter is going to be diferent. i hope this helps.....
2007-01-01 02:07:27 · answer #1 · answered by randy b 1 · 1⤊ 0⤋
Helicopter blades do not travel at the speed of sound or above (supersonic), this being said, if you have a helicopter that has four blades on the rotor, four of the classic "whap,whap" sounds, equals one rotation, same if you have two or three rotors, the number of "whap, whap" sounds that you hear, if it is equivalent to the number of blades, that equals 1 revolution
2007-01-01 14:25:08 · answer #2 · answered by mcdonaldcj 6 · 0⤊ 0⤋
Since chopper blades are NOT transsonic, what you hear is what you get.
2007-01-01 02:11:30 · answer #3 · answered by Kasey C 7 · 0⤊ 1⤋
Depends on how far away you are.
2007-01-01 02:46:32 · answer #4 · answered by Anonymous · 4⤊ 0⤋
it depentds on how fast it is spinning but probably alot
2007-01-01 17:00:41 · answer #5 · answered by Anonymous · 0⤊ 1⤋