Download Blood Spatter Web Quest - Word Doc

Name: ______________________________ Date: _____________ Period: ______ ID: ______
Mr. Beatty
Forensics
Blood Spatter Webquest
Visit the following website and complete the Blood Spatter Animation guide:
http://projects.nfstc.org/gallery/main.php?g2_itemId=3857
Tab through each of the three areas and answer the following questions:
Tab 1: Drop Flight Dynamics
1. Why is blood pulled to the lowest point on a weapon like a knife covered with blood?
2. What three forces are involved in eventually causing the drop of blood to fall?
3. What addition “property of matter” comes in to play if a weapon with blood is swung?
4. What is a “passive drop” and what is its shape?
5. Once the drop of blood is in “free fall” what is its shape?
6. Define “spheroid” and “spheroid-oblong.”
7. At what point does the drop return to a perfect sphere?
8. Now for some Physics: What two forces act on a falling drop of blood?
9. Which force causes acceleration?
10. Which force causes deceleration?
11. What is terminal velocity
12. In air, why do larger drops of blood reach greater velocities than smaller ones?
Name: ______________________________ Date: _____________ Period: ______ ID: ______
Mr. Beatty
Forensics
Tab 2: The 4 Phases of Impact
1. During contact with a surface, collapse occurs from which direction?
2. In which direction does the displaced blood pushed?
3. What forms on the perimeter of the blood drop during Displacement?
4. What does “inertia” do to remaining blood in the middle of the drop?
5. What forms on the edge of the drop?
6. How would you describe the shape of the drop as viewed from the top?
7. During the dispersion phase, what new type of spatter results?
8. How would you describe the shape of these new spatters?
9. During retraction, which force finally halts the spread of satellite spatter?
Tab 3: Angle of Impact
1. What is the shape of the stain [spatter] that results when the droplet strikes the surface at
a 90o angle?
2. How are the spines, scallops and satellites distributed around the perimeter of the drop?
3. At one angle can you first detect a change in the shape of the drop?
4. Is there any difference in the satellite spatter at angle 70?
5. What is the difference in shape of the droplet between 60o and 45o?
6. Finally, what is the difference in shape between the shape of the droplets between 45o and
25o?