Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Linear Functions
• Science: Forensics: Time of death (rate of decay)

9-12

60 Minutes

• ##### Device
• TI-83 Plus Family
• TI-84 Plus
• TI-84 Plus Silver Edition
• TI-84 Plus C Silver Edition
• TI-84 Plus CE
• ##### Software

TI Connect™
TI Connect™ CE

• ##### Accessories

Sensor - Temperature
TI Connectivity Cable

• ##### Other Materials
This is Activity 14 from the EXPLORATIONS Book:
Forensics: Connecting Science Investigations with TI Data Collection Activities.

The following materials are required for this activity:
• Vernier EasyTemp™ temperature probe
• Ring stand with clamp
• Model victim

## Forensics Case 14—Hot Air, Cold Body: Using Newton's Law of Cooling to Determine Time of Death

#### Activity Overview

Students create a temperature versus time graph for cooling and become familiar with Newton's Law of Cooling. They use the cooling-rate equation to estimate time of death of the victim.

#### Key Steps

• To be able to calculate the cooling constant of air, students use a model "victim" (such as water lock in a container or warm potato) to make a cooling curve.

• With the data from the time-graph, students have the option of using the equation solver to calculate the cooling constant of air.  From the paramedic's report, students can use the constant to estimate the victim's time of death.