diff --git a/notes/phys1/phys1_extra.txt b/notes/phys1/phys1_extra.txt
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+--- ELASTIC COLLISIONS ---
+(vA' and vB' are final velocities)
+
+vA' Formula:
+vA=((m1-m2)/(m1+m2))*v1+(2*m2/(m1+m2))*v2
+
+vB' Formula:
+vB=(2*m1/(m1+m2))*v1+((m2-m1)/(m1+m2))*v2
+
+--- TORRICELLI (NO TIME) ---
+(vf = final, vi = initial, a = accel, d = dist)
+
+Final Velocity:
+vf=sqrt(vi^2+2*a*d)
+
+Distance/Displacement:
+d=(vf^2-vi^2)/(2*a)
+
+Acceleration:
+a=(vf^2-vi^2)/(2*d)