How do you calculate the distance between the fin Root Cord line and the mean aerodynamic chord line?

(Google Gemini Pro Credit)

Calculate the rocket fin Spanwise Distance for the mean aerodynamic chord when Cr=9, Ct=1, S=3

Python

# Define the given variables
Cr = 9  # Root Chord
Ct = 1  # Tip Chord
S = 3   # Span

# Calculate the Spanwise Distance (y_MAC)
y_MAC = (S / 3) * (Cr + 2 * Ct) / (Cr + Ct)

print(f"Cr = {Cr}")
print(f"Ct = {Ct}")
print(f"S = {S}")
print(f"Spanwise Distance (y_MAC) = {y_MAC}")
Code output
Cr = 9
Ct = 1
S = 3
Spanwise Distance (y_MAC) = 1.1

The rocket fin’s spanwise distance for the mean aerodynamic chord ($y_{\text{MAC}}$) is $1.1$.

This value tells you how far out from the rocket’s body (the fin root) the mean aerodynamic chord is located.

Calculation

Here is the step-by-step calculation using the standard formula.