Sound waves generated in a classroom must through an open doorway in order to propagate into the hallway. reflect refract diffract

Sound waves generated in a classroom must diffract  through an open doorway in order to propagate into the hallway. 

Answer;

Diffract

Sound waves generated in a classroom must diffract through an open doorway in order to propagate into the hallway.

Explanation;Sound waves are a type of mechanical waves that requires a material medium for transmission, they are longitudinal wave with all the properties of other waves.Diffraction is one of the property of waves that involves a change in direction of waves as they pass through an opening or around a barrier in their path. Sound wave diffract around corners or through the door openings, allowing people to hear others speaking to us from rooms that are adjacent.

Gravity bc it’s gravity