If air in the room is warmed up, the speed of sound in it(1) increases(2) decreases(3) remains the same(4) fluctuates

Analyzing the Effect of Temperature on the Speed of Sound

When air in a room is warmed up, the characteristics of sound waves traveling through that air are affected primarily by the temperature of the medium (in this case, air). The speed of sound in a gas is influenced by the kinetic energy of the molecules. As the temperature increases, the kinetic energy of the air molecules also increases, causing them to move faster.

1. The Kinetic Molecular Theory: According to this theory, the speed of sound is directly proportional to the square root of the absolute temperature. The formula can be expressed as: $c = \sqrt{\frac{\gamma \cdot R \cdot T}{M}}$ Here, $c$ is the speed of sound, $\gamma$ is the adiabatic index (ratio of specific heats), $R$ is the universal gas constant, $T$ is the absolute temperature in Kelvin, and $M$ is the molar mass of the gas.

2. Temperature and Speed of Sound: As the temperature $T$ increases, the term inside the square root also increases, resulting in an increase in the speed of sound $c$.

Conclusion

Given this understanding, warming the air leads to an increase in the speed of sound. Thus, the correct answer is:

(1) increases.

This conclusion aligns with our knowledge of the physical properties of sound in gases and reflects a fundamental principle of thermodynamics.