Sound waves are generated by a rock falling into the sea. The sound waves travel through water and through air, traveling faster through water than through air. The figure shows a lifeguard and a swimmer. The lifeguard is on the beach, 20 meters away from where the rock lands, and the swimmer is underwater, 20 meters away from where the rock lands. Who would the first person to hear the splash made by the rock be, the lifeguard or the swimmer?
The swimmer would be the first person to hear the splash made by the rock. Since sound waves travel faster through water than through air, the sound waves would reach the swimmer underwater before they reach the lifeguard on the beach.
