Question

Which of the following is a type of wave that does not need a medium though which to travel? Equilibrium Longitudinal Amplitude Transverse

Answer 1

Longitudinal waves like sound waves occur when particles oscillate in the same plane as the direction of travel of the wave. They are basically pressure waves that move through some medium. In a vacuum there are no particles to oscillate, nothing for a pressure wave to travel through. So since all longitudinal waves are pressure waves and pressure requires a medium then these waves cannot exist in the vacuum of space where there is no medium.

Answer 2

Thanks :)