Question

how is amplitude related to loudness

Answer 1

amplitude is related to loudness because the magnitude of the maximum dissturbance in a medium on either sides of the mean position
loudness
loudness - is how our sound enters our ears

Answer 2

Hey there!

Relation between Loudness and Amplitude:

Loudness is directly proportional to square of the amplitude.

i.e Loudness ∝ (Amplitude)²

Example:

When a body vibrates with a greater amplitude, it sends forth a greater amount of energy and hence the energy received by the eardrum is large, so the sound appears louder.

Hope It Helps You!