Forensics and Mathematics Ricky Pedersen De La Salle College

Forensics and Mathematics

Ricky PedersenDe La Salle College

Newton’s Law of Cooling


• You may wish to choose a volunteer to “play dead”

• Police tape is a bonus!

• Fake blood


Achievement Standards 3.7 & 2.2Curriculum Levels 7 - 8

Learning Outcomes:

• Solve Logarithmic equations for an unknown

• Graph Logarithmic equations


Things to watch out for:

Students may not know that k is specific to the body

They may also assume that the cooling rate of bodies is linear

Suspect Radius

Suspect Radius

Who could have done it?!?!?!

• Time of Death established with Newtons Law of Cooling – hopefully between classes

• Teacher must have walked to and from class in the transition time

(2 minutes)

Suspect Radius

Achievement Standards 2.2, 2.14, 3.1Curriculum levels 5-8

Learning Outcomes:• Graphing the equation of a circle or

ellipse and finding the equation• Determine whether a point lies in

the interior or exterior of a circle/ellipse based on the equation

Suspect Radius

Students will need to

• Decide on a suitable stride and speed at which a teacher would walk

• Using a map they can mark out possible suspects and rule out teachers who are not in the radius

Suspect Radius

Guide the students

• Even though it is 2 minutes between classes, the circle radius would have to be halved

• The maximum distance can be found using the distance equation

Suspect Radius

Extension

• Use buildings with multiple levels

• Add in extra information – “Mr Pedersen was seen arguing with Ms Yang in the morning”

Suspect Height

Suspect Height

Time to identify the suspect!

• You will need a shoe print…preferably not a high heel

• Discussion for students - what use is this shoe print to us?

Suspect Height

Achievement Standards 1.4, 1.6, 1.11Curriculum levels 4-6

Learning Outcomes:• Substitution with variables • Measuring and managing sources of

variation• Using an explanatory variable to

predict a response variable

Suspect Height

• Useful tools – iNZight or censusatschools database

• Provide an equation if you’re lazy • Good opportunity to do hands on

practical measuring!

Bone Lengths and Height


These bones can be used to identify the height of a person

• Femur (thigh)• Humerus (arm)• Tibia (shin)• Radius (forearm)


Achievement Standards 1.2 & 1.4Curriculum levels 4 - 6

Learning Outcomes:

• Substitution with variables• Rearranging and using formulae • Linear graphing


Male measurements

Height = 69.089 + 2.238 F Height = 81.688 + 2.392 T Height = 73.570 + 2.970 H Height = 80.405 + 3.650 R


Female measurements

Height = 61.412 + 2.317 F Height = 72.572 + 2.533 T Height = 64.977 + 3.144 H Height = 73.502 + 3.876 R


• How tall is a male if his femur is 46.2cm long?

• If a female is 152cm tall, how long is her humerus?

• In order to ride a rollercoaster, your tibia should be at least 30cm’s. How tall does a male need to be?


• Graph the equation for a male and female radius on the same grid.

• What length radius will produce a male and female of the same height?

• What does the x and y intercepts mean in this context?

Blood Spill

Blood Spill

Other activities using blood….

• Let’s have a look at the blood spill (hopefully not stain)

• You can either use liquid or cut out paper

Blood Spill

Achievement Standard 1.6 & 3.6Curriculum levels 4-6 and 7-8

Learning Outcomes:

• Calculate the area of compound shapes

• Calculate rates of change

Blood Spill

• Draw up a unique blood spill which is non uniform in shape

• Students to calculate the area of this spill.

Blood Spill

• Draw up several uniform blood spills

• Get students to measure the radius of the circles (as best they can)

• Calculate the rate of change of the area for different values of dr/dt

Blood Spatter Analysis


Achievement Standard 1.6 & 1.7Curriculum levels 4 – 6

Learning Outcome:

• Calculate unknown angles and sides of right angled triangles


• When blood drops hit the ground, they stretch depending on the angle

• Students can simulate this using an eye dropper and beetroot juice

• Angle the paper, not the dropper!



TeachersDesk

Documents

Forensics and Mathematics Ricky Pedersen De La Salle College