# AP Physics B : Waves

## Example Questions

### Example Question #1 : Waves And Optics

In the electromagnetic spectrum, __________ have the highest frequency and __________ have the greatest energy per photon.

gamma rays . . . gamma rays

ultraviolet light . . . X-rays

X-rays . . . radio waves

microwaves . . . microwaves

infrared light . . . ultraviolet light

gamma rays . . . gamma rays

Explanation:

The relationship between frequency and energy is determined by Planck's constant in a direct relationship. This means that as frequency increases, energy increases as well.

The electromagnetic waves with the highest frequency will have the greatest energy per photon, and vice versa.

In the electromagnetic spectrum, radio waves have the lowest frequency (largest wavelength) and gamma rays have the highest frequency (shortest wavelength). Gamma rays will thus have the highest frequency and greatest energy.

### Example Question #1 : Ap Physics 2

Two in-phase waves travelling in the same direction with the same period have amplitudes of  and , respectively. A third, out-of-phase wave with the same period as the other two has an amplitude of . What will be the amplitude of the final resultant wave when these three are aligned?