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anonymous
 one year ago
The amplitude of a wave is A and intensity is I. Which amplitude is neccessary for the intensity to be doubled to 2I?
a. A^2
b. √A
c.√2A
d. 2A
anonymous
 one year ago
The amplitude of a wave is A and intensity is I. Which amplitude is neccessary for the intensity to be doubled to 2I? a. A^2 b. √A c.√2A d. 2A

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Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.3the intensity is proportional to the square of the amplitude

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I=kA^2 so i multiplied both sides by two to get 2I=2A^2 am i right?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.3yes! correct! So, the new amplitude is: sqrt(2)*A

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0But wouldn't it give √2I too? Or it doesn't matter ?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.3no the intensity is 2*I, so we can write: \[2I = K{A^2} + K{A^2} = 2K{A^2} = K{\left( {\sqrt 2 A} \right)^2}\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.3so the new amplitude is: \[{\sqrt 2 A}\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0But if we square root one side of the equation won't we do the same to the other side? So it becomes like √2I=k√2A ?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.3I haven't squared root the sides of that equation. The new intensity is 2*I, and as all intensities, it has to be proportional to the square of some amplitude, so I can write: \[\Large 2I = K{B^2}\] where B is the new amplitude. Now comparing that equation with the previous equation: \[\Large 2I = 2K{A^2}\] we can write: \[\Large {B^2} = 2{A^2}\] and taking the square root, we get: \[\Large B = \sqrt 2 A\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ohh! I get it if you put √2A in 2I=kB^2 you get 2A^2 THANKYOU SO MUCH !!!!
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