Question

As the temperature of a medium increases, the speed of the sound wave

increases because the particles bump into each other more often.
increases because the particles bump into each other less often.
decreases because the particles bump into each other more often.
decreases because the particles bump into each other less often.

Answer 1

Increases because the particles bump into each other more often.

Reason: for a gas c = sqrt(γRT/M), so c ∝ sqrt(T). Higher temperature means faster-moving molecules, more frequent collisions, and faster transmission of pressure disturbances (sound).