Effect of different impact surfaces on blood splatter
Experiment: Effect of different impact surfaces
Hypothesis: the rougher the impact surface the edgier the drop of blood will be and the smaller the diameter of the blood splatter will be.
Independent variable: the impact surface material. Dependent: The diameter and shape of the blood splatter Controlled variable: the height of releasing the blood. The position of the impact surface. Materials: - Chocolate icing dyed red - 1 piece of tile - 1 piece of A4 paper - 1 chopping board - 1 piece of lino - 1 camera - 1 ruler Method:
Pictures: see right. (from left to right: film, tile, paper, wood, lino) Analysis: The drop of blood on the tile and the film are both relatively round without any serrated edges. The shapes of 2 blood drop look the same and they're both the same size. This is because film and tile both have the same smoothness to their surfaces. The drop of blood on the paper (first row, the one to the right picture) appears to be fairly round. However it is not as smooth and round as the first two if being examined closely. Paper is not as smooth as film and tile. The drop of blood on the piece of wood has serrated edges. It is visible on the image that the piece of wood is not smooth, it has bumps and little holes in it. So the diameter of the blood drop is decreased on the wood surface. The drop of blood on the piece of lino also has serrated edges. Lino, just like wood, has holes and bumps on its surface so this would cause the drop of blood to be edgy. Discussion: What effect does different impact surface have on the diameter and shape of the blood splatter?
Besides different surfaces of impact, there are other factors that can affect the shape of blood splatter as well. Take a look at the article here to find out more about how blood splatter is extremely valuable in crime scene investigations. |