(15C) Speed of Sound in Air

[Eddie W. Shore]

Formula used:

The speed of sound in air can be approximated by:
c ≈ √( γ * R * T / M)

where:

R = molar gas constant = 8.314 4625 618 153 J/(K * mol)
R = 8.314 4625 618 153 (kg * m^2)/(s^2 * K * mol)

M = molar mass of air = 0.02897 kg/mol

γ = adiabatic index of air = 1.4


C ≈ 20.04503702 * √T ≈ 331.2893427 * √((°C + 273.15) / 273.15)


Instructions:

To calculate the speed of sound when the temperature is in Fahrenheit (°F), press [ f ] { A } or [ GSB ] { A } [ R/S ].

To calculate the speed of sound when the temperature is in Celsius (°C), press [ f ] { B } or [ GSB ] { B } [ R/S ].

To calculate the speed of sound when the temperature is in Kevin (K), press [ f ] { C } or [ GSB ] { C } [ R/S ].

Code:

Code:


Step ; Key Code ; Key
001 ; 42, 21, 11 ; LBL A
002 ; 3 ; 3
003 ; 2 ; 2
004 ; 30 ; -
005 ; 5 ; 5
006 ; 20 ; ×
007 ; 9 ; 9
008 ; 10 ; ÷
009 ; 42, 22, 12 ; LBL B
010 ; 2 ; 2
011 ; 7 ; 7
012 ; 3 ; 3
013 ; 48 ; .
014 ; 1 ; 1
015 ; 5 ; 5
016 ; 40 ; +
017 ; 42, 22, 13 ; LBL C
018 ; 11 ; √
019 ; 2 ; 2
020 ; 0 ; 0
021 ; 48 ; .
022 ; 0 ; 0
023 ; 4 ; 4
024 ; 5 ; 5
025 ; 0 ; 0
026 ; 3 ; 3
027 ; 7 ; 7
028 ; 0 ; 0
029 ; 2 ; 2
030 ; 20 ; ×
031 ; 36 ; ENTER
032 ; 36 ; ENTER
033 ; 2 ; 2
034 ; 48 ; .
035 ; 2 ; 2
036 ; 3 ; 3
037 ; 6 ; 6
038 ; 9 ; 9
039 ; 3 ; 3
040 ; 6 ; 6
041 ; 20 ; ×
042 ; 34 ; X<>Y
043 ; 43, 32 ; RTN

Examples:

68 °F: 68 [ f ] { A } -> 343.20358 m/s, 767.72445 mph
35 °C: 35 [ f ] { B } -> 351.87462 m/s, 787.83024 mph
280 K: 280 [ f ] { C } -> 335.41762 m/s, 750.30776 mph

Source

“Speed of Sound” Wikipedia. Last Edited March 27, 2024. https://en.wikipedia.org/wiki/Speed_of_sound Retrieved April 7, 2024