FSC239Y5 Lecture Notes - Lecture 5: Blunt Trauma, Blood Residue, Surface Tension
Document Summary
Blood stain pattern interpretation: the blood static or inert, dropping or gushing, projecting or erupting will follow the laws of physics. 6) distance from the blood source direction of travel and impact nature of the force object used sequence of multiple bloodshed interpretation. Surface tension is defined as the force that pulls the surface molecules of a liquid towards its interior, decreasing the surface area and causing the liquid to resist penetration. It causes the blood drop to pull itself in, both horizontally and vertically. To create spatter, an external force must overcome the surface tension of blood. An avg size free falling blood drop (0. 05mm) terminaly velocity 25. 1ft/s blood forms a spherical shape (perfect circle) almost immediately upon separating from the blood source. Target surface texture on glass will form proper circle, on carboard or paper, will be an irregular circle.
