Question

what does it mean when an electromagnetic wave has low energy? it has a long wavelength. it has a high frequency. it has a short wavelength.

Explanation:

The energy of an electromagnetic wave is related to its frequency and wavelength. The formula for the energy of a photon (a quantum of electromagnetic radiation) is \(E = h
u\), where \(h\) is Planck's constant and \(
u\) is the frequency. Also, the speed of light \(c=\lambda
u\) (where \(\lambda\) is the wavelength), so \(
u=\frac{c}{\lambda}\). Substituting into the energy formula gives \(E = \frac{hc}{\lambda}\). This shows that energy \(E\) is inversely proportional to wavelength \(\lambda\). So, a low - energy wave has a long wavelength.

Answer:

It has a LONG wavelength.