A Level Physics: Intensity is proportional to the amplitude squared

An explanation plus some questions with solutions.
Hope this is useful!

Chapters:
00:00 What is intensity?
00:41 Intensity and Amplitude
03:54 Practice Problems

[samizarroug]

This was in paper 2 today, the intensity amplitude truck helped so much thank you !!

[aishasyafika]

I have difficulty in understanding this for soooo long. Thank you!

[QuaternionPhysics]

Best channel for Physics, you're amazing!

[KhantHtalJu]

Hel..lo, sir .is there another formula that respect to intensity and amplitude? If we derive the formula like this
I varie A square
I = constant × A square
I/A square =constant
So,
I/Asquare =I'/A' square
I wanna know is that right?

[adibaislam]

doesnt the cm have to be converted to m?
at 5:26

[jozifff.]

why r y doing x10^-2 if it’s already in cm? 7:03

[KhantHtalJu]

Hel...lo, sir I wanna know SI unit of constant k . I think it would be watt per fouth meter.But I'm not sure yet. And I don't know whether it's right or wrong .please teach me sir.🙏🙏🙏🙏

[S.C.A._U]

thank you so much, but maybe can just explain to me, why is the amplitude squared

[cassandraMD]

In question 2, should k = 100/ 10^-2x 10^-2 = 1 million ?

[lanadelreysguitar]

Sir when do we use w²a² and when do we use a²

[Hanan]

the first question you did is wrong. You didn't convert the amplitude to meters