Sound speed varies with air temperature. The temperatures of air will be either low or high.

Case 1 :— When air temperature is low.

As the temperature of air decreases, the air molecules become more and more rigid. The vibrating capacity of the molecules reduces. Sound is a series of waves which vibrate the molecules to transmit the energy.

As the temperature is low, the molecules vibrate lesser and lesser. Due to less vibrations, the energy takes a longer period of time to get transmitted.

So, the speed of sound is low at lower temperatures.

Case 2 :— When temperature of air is high.

The converse of the above situation is also true. The air molecules vibrate more and more due to higher temperatures. High temperature means sound waves easily travel the distance in a much shoter time.

I have very small answers

The sound velocity is directly proportional to the increase in temperature because as the temperature increases the air molecules starts vibrating at higher amplitude thus making the travel of sound easier. Generally, the speed of sound in air increases with temperature.