diff --git a/mechanical/mmme1028_statics.md b/mechanical/mmme1028_statics.md
index 92eb438..86564a6 100755
--- a/mechanical/mmme1028_statics.md
+++ b/mechanical/mmme1028_statics.md
@@ -500,7 +500,7 @@ E &= \frac \sigma \epsilon = 2513836.686 = 2.5\times10^6 \text{ Pa}
 
 ## Poisson's Ratio
 
-For most materiajs, their cross sectionts change when they are stretched or compressed.
+For most materials, their cross sectionts change when they are stretched or compressed.
 This is to keep their volume constant.
 
 $$ \epsilon_x = \frac {\Delta L}{L_0} $$