I was wondering that the annoying buzzing sound from a mosquito is produced when it flaps its wongs at an average rate of 600 flaps per second.
a) what is the frequency of the sound waves?
b) what is the period of these sound waves?
as long as I know there is no centre of the universe! According to the standard theories of cosmology, the universe started with a "Big Bang" about 14 thousand million years ago and has been expanding ever since. Yet there is no centre to the expansion; it is the same everywhere. The Big Bang...