Answer:
A law stating that in fluorescence the wavelength of the emitted radiation is longer than that of the radiation causing it. This is not true in all cases.
Explanation:
<span>You need to find the path difference. That is, how much further must sound waves from the more distant speaker travel than the close speaker, to reach the mike.
Use Pythagoras to find the distance of the further speaker: it is √(2.00²+4.50²)=4.924m so the path difference is 4.924-4.50=0.424m.
You will get constructive interference when this path difference is an integer number of wavelengths, because the waves will arrive at the mike in phase.
The speed of sound is 340m/s so the lowest frequency that will produce an antinode at the mike is the one that makes 0.424=λ
v=fλ so f=v/λ
f=340/0.424=801Hz.
The next one will be when 0.424m = 2λ => λ=0.212m
f=340/0.212=1602Hz
and so-on according to f=340n/0.424 where n is an integer.
For destructive interference the path difference must be (n-½)λ because that will make the waves arrive at the mike 180° out of phase.
f=340(n-½)/0.424</span>
I’m not sure what you are asking
Answer:
C. 233 km/h
Explanation:
Ground speed = air speed + wind speed
250 km/h = v + 17 km/h
v = 233 km/h
The velocity of the wave on the string is given by
Solving the above equation,
The frequency of the wave 
and wave length is 
The velocity is 
Substituting numerical values,
The length of the string is 
