How do you calculate the wavelength of a wave with an energy???? (1 Viewer)

[daisy_22]

 

[Drongoski]

I'm no expert in physics.
Here you have a simple relationship connecting 4 quantities:
From elementary algebra, if you know any 3 of these 4, you can find the 4th one. Here you want to find lambda, the wavelength; since you know the other 3, you should be able to find the 4th. E is given. c is the speed of light. h is Planck's constant, all of which you know.

 

[wizzkids]

The first thing to note about this question is, it doesn't state what sort of wave we are talking about. However, it is pretty clear this must be an electromagnetic wave, because energy is quantised. For all other sorts of waves, like water waves, waves on strings, sound waves etc. the energy cannot be quantised with the relation shown. That is why it is possible, in the case of electromagnetic waves, to relate energy to wavelength through the equation that is given. This discovery, made by Max Planck in 1900, marks the end of the era of Classical Physics and the start of the era of Quantum Physics.

 

[Eagle Mum]

BTW, note that because h and c are both constants, E and λ are inversely proportional to each other, so the shorter the wavelength, the higher the energy of the electromagnetic radiation wave, which is why UV light (which has shorter wavelengths than visible light) causes sunburn and skin damage and X rays (even shorter wavelengths and higher frequencies) are a type of ionising radiation which can damage DNA.