This is a lesson I use to introduce my physics students to the process of scientific investigation including writing a problem statement, generating a hypothesis, collecting and organizing data, analyzing data, writing a conclusion that is supported by data, and communicating results in a lab report. It also serves as a motivational activity to get students excited about investigating the world around them.
I present the class with the challenge of determining what happened at the scene of the "Clean Getaway." I provide them with a series of digital photos taken of parts of the floor at the crime scene. Each photo includes a protractor for scale.
Step 1: Required Materials
Materials for making fake blood:
shampoo (this is why its called the clean getaway!)
a generous amount of red food coloring
a few drops of blue food coloring
The amount of coloring you need depends on the original color of the shampoo. Once you think you have a good color, smear a little on white paper to see the color.
disposable gloves for students
lab aprons for students
large knife smeared with fake blood and put inside evidence bag (I used a plastic baggie with a zipper closure.)
supply of fake blood for students
prepared crime science blood spatters
access to a computer
photo analysis software