Question

which of the following are true concerning electromagnetic waves? select all that apply. as electromagnetic waves increase their speed, they increase their frequency. x-rays have shorter wavelengths than microwaves. electromagnetic waves with higher frequencies have shorter wavelengths. radio waves travel the same speed as gamma rays, but their wavelengths are longer, and their frequencies are less. radio waves travel slower than gamma, and their wavelengths are longer.

Explanation:

• For electromagnetic waves in a vacuum, speed \(c = \lambda f\) (where \(c\) is the speed of light, \(\lambda\) is wavelength, and \(f\) is frequency). The speed of electromagnetic waves in a vacuum is constant (\(c\approx3\times 10^{8}\space m/s\)), so the statement "As electromagnetic waves increase their speed, they increase their frequency" is false.
• In the electromagnetic spectrum, X - Rays have shorter wavelengths than microwaves.
• From \(c=\lambda f\), when \(c\) is constant, higher frequency (\(f\)) implies shorter wavelength (\(\lambda\)).
• All electromagnetic waves (including radio waves and gamma rays) travel at the speed of light (\(c\)) in a vacuum. Using \(c = \lambda f\), radio waves (with lower frequency \(f\)) have longer wavelengths \(\lambda\) compared to gamma rays (with higher frequency \(f\)).
• Radio waves and gamma rays travel at the same speed (\(c\)) in a vacuum, so the statement "Radio waves travel slower than gamma, and their wavelengths are longer" is false.

Answer:

• X - Rays have shorter wavelengths than microwaves.
• Electromagnetic waves with higher frequencies have shorter wavelengths.
• Radio waves travel the same speed as gamma rays, but their wavelengths are longer, and their frequencies are less.