Function that calls other functions

Hello everyone.

I have an issue with calling a couple functions to return the desired value. What I am trying to do is get the type of material and its thickness and output time in seconds that sound will take to go through the material. Here is the code I have so far:


Option Explicit


Public Function GetSpeedOfSound(strMaterial As String) As Double
Select Case LCase(strMaterial)
Case "air"
GetSpeedOfSound = 1126.1 'this case returns 1126.1 feet per second
Case "water"
GetSpeedOfSound = 4603.2 'this case returns 4603.2 feet per second
Case "steel"
GetSpeedOfSound = 20013.3 'this case returns 20013.3 feet per second
Case "earth"
GetSpeedOfSound = 22967.4 'this case returns 22967.4 feet per second
End Select
End Function

Public Function GetInverseSpeed(strMaterial As String) As Double
GetInverseSpeed = 1 / GetSpeedOfSound(strMaterial)
End Function

'purpose: get the type of material and its thickness and output time in seconds that sound will take to go through the material
'param strMaterial: a string specifying the kind of material ("air", "water", "steel", "earth")_
'param dblThick: a double specifying the amount of thickness of the material
'returns: the number of seconds it takes for sound to go through thickness of the material
Public Function GetSpeedThroughMaterial(strMaterial As String, dblThick As Double) As Double
GetSpeedThroughMaterial = GetInverseSpeed(strMaterial) + GetSpeedOfSound(strMaterial)
End Function


The first two functions are working as they should, but I am not sure how to write the GetSpeedThroughMaterial function to return the desired calculation. All I know is that I should be able to accomplish this task with one line of code. I know I'm over thinking this, but for some reason it's just not clicking for me. Any help would greatly be appreciated. Thank you!

Hello and thank you for the quick responses! MrShorty, sorry for the ambiguity of the code but the I believe the correct line of code was the first one you provided. Shg, thank you as well for spelling it for me so clearly . You guys rock and thanks again!