Forensic Lamp Examination (Screencast)
This learning object is designed to assist students in understanding and interpreting collision evidence found in automotive lamps. In particular, the concepts of Hot Shock, Cold Shock, Hot Break, and Cold Break will be visually addressed.
This screencast shows how blood droplets are held together by a strong cohesive molecular force that produces surface tension in each drop and on the external force. Surface tension pulls the surface molecules of a liquid toward its interior, decreasing the surface area and causing the liquid to resist penetration.
In this learning object the student will learn that regardless of the surface onto which a blood droplet is falling, the angle or velocity at which it does so, or the volume of the droplet, there are four distinct phases involved in the reaction of a moving droplet with impact against a surface.