Question

When x-ray radiation and infrared radiation are

traveling in a vacuum, they have the same
(1) speed (3) wavelength
(2) frequency (4) energy per photon

Answer 1

When x-ray radiation and infrared radiation are traveling in a vacuum, they have the same speed.

Answer 2

The correct answer is

(1) speed

In fact, the speed of an electromagnetic wave does not depend on the type of wave, but only on the medium: since both the waves are travelling in vacuum (same medium), they are travelling at same speed, which corresponds to the speed of light in vacuum:

`c=3.0 \cdot 10^8 m/s`