diff --git a/ps16-1.py b/ps16-1.py
index 7f47742..fbeb60c 100644
--- a/ps16-1.py
+++ b/ps16-1.py
@@ -2,7 +2,6 @@ import numpy as np
 import pylab as pl
 
 a = 5
-F = 4000
 D = 1
 hbar = 1
 m = 1
@@ -20,6 +19,7 @@ x_pos = x[x > 0]
 z0 = (a / hbar) * np.sqrt(2 * m * V0)
 print(f'z0 = {z0}')
 k = -l * cot(l * a)
+F = np.sin(l * a) / np.exp(-k * a)
 
 psi_conditions = [
     (0 < x_pos) & (x_pos <= a),