Two pianos each sound the same note simultaneously, but they are both out of tune. On a day when the speed of sound is 343 m/s, piano A produces a wavelength of 0.762 m, while piano B produces a wavelength of 0.781 m. How much time separates successive beats?

time period = 0.09 s

Explanation:

given data

speed of sound v = 343 m/s

wavelength λ1 = 0.762 m

wavelength λ2 = 0.781  m

solution

we know that beat frequency is the difference between the frequency of the individual wave so

frequency f1 =   ..........................1

frequency f1 = = 450.13

and

frequency f2 =     = 439.18

so beat frequency = f1 - f2

beat frequency = 450.13 - 439.18

beat frequency = 10.95 Hz

and

time period between successive beats is

time period =  

time period =

time period = 0.09 s

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it