Question

A child is swinging back and forth on a playground swing - five different positions are shown on the diagram, and marked 1-5. A speaker in front of the child is broadcasting a single-frequency tone.

At which point in the swing does the child perceive the sound to be loudest?

At which point in the swing does the child perceive the sound to be of lowest frequency?

At which point in the swing does the child perceive the sound to be of highest frequency?