The speed of sound in air at 0 degrees Celsius (273.15 Kelvin) and absolute pressure of 1 bar (100,000 Pascals) is approximately 331.4 meters per second (1,087 feet per second).

Here's why:

* Temperature: The speed of sound is directly proportional to the square root of the absolute temperature.

* Pressure: At standard atmospheric pressure, the speed of sound is relatively insensitive to changes in pressure.

Formula:

The speed of sound in air can be calculated using the following formula:

```

v = sqrt(γ * R * T)

```

Where:

* v is the speed of sound

* γ is the adiabatic index of air (approximately 1.4)

* R is the specific gas constant for air (287 J/(kg·K))

* T is the absolute temperature in Kelvin

Calculation:

```

v = sqrt(1.4 * 287 J/(kg·K) * 273.15 K)

v ≈ 331.4 m/s

```

Note: This is a theoretical value. In reality, factors such as humidity and the presence of other gases can slightly affect the speed of sound in air.