Blood splatter

Blood splatter 1 

 Blood Splatter 2

 Blood Splatter 3

 Blood Splatter 4

Blood Splatter 5

Blood splatter Pattern from a Laboratory Experiment by Mr Leong TK & Chua HL

What is the shape of the blood splatter?

It is mostly round and oval.

Describe any other characteristic of the splatter

1. Drip

2. Slammed against the thing

3. The person staggered and collapsed 

4. Slammed repeatedly against the wall, slid down

What are the factors that affect the shape of the blood splatter? Name as many as possible.

- Size of wound

- Depth of wound

- Position of person

- Height of the person

- Contact with blood splatter 

Generate some hypothesis from the blood splatter patterns observed above. 

- The greater the angle of elevation, the longer the blood splatter

- The greater the angle of elevation, the narrower the blood splatter

- The greater the angle of elevation, the smaller the angle of impact

- The larger the distance between the the blood splatter and the wound, the wider the blood splatter

Experiment one: Height

Height/cm	WA / mm	WB / mm	WAve / mm
10	8mm	8mm	8mm
30	10mm	11mm	10.5mm
60	11mm	12mm	11.5mm
100	13mm	13mm	13mm
150	12mm	14mm	13mm

Experiment 2: Angle 

Angle of elevation / °	LP / mm	LQ / mm	LAve / mm	WP / mm	WQ / mm	WAve / mm
10	13mm	15mm	14mm	13mm	14mm	13.5mm
30	15mm	16mm	15.5mm	13mm	13mm	13mm
50	19mm	19mm	19mm	11mm	11mm	11mm
70	28mm	26mm	27mm	9mm	9mm	9mm

Graphs: 

Height (Width) 

 Angle of elevation ( Length)

 Angle of elevation(Width)

 Angle of elevation VS angle of impact

Pictures: 

 Experimental Set up

 Blood splatters ( Height)

 Blood splatters (Height)

Blood splatters (angle)

Part 2: 

This is the blood splatter patterns created by my group. 

Analysis:

 From this activity, I gathered that all my hypothesis were true. 

1. Height: This factor was a little difficult to test out as the butcher sheet was pasted vertically on the wall, but nevertheless, true. 

2. Angle of elevation: From the blood splatter patterns made, it shows that blood splatters are longer and narrower when blood is dripped from a certain angle. 

3. Angle of impact: The above pattern shows that the angle of impact is smaller when the blood is dripped from a certain angle. 

Explanations: 

- Height. 

The height from which the droplet falls affect the velocity of the droplet of blood. The velocity of the blood will in turn affect the width of the blood splatter. So, as the droplet remains airborne for a longer period of time, the velocity of the droplet changes, causing the width of the splatter to change as well. 

- Angle of Impact

The angle of impact on a flat surface can be calculated by measuring the length and width of a stain. The angle of impact is the acute angle that is formed between the direction of the blood drop and the surface it strikes. The stain will be more elliptical when the angle of impact increases. This is an important measure because it is used to determine the area of convergence and the area of origin.

- Elongation
As the blood splatter is elongated, the width of the splatter becomes narrower. The angle of impact will also increase when the difference between the length and width of the splatter increase.