Imagine a murder has been committed and the body is cooling. A Crime Scene Investigator (CSI) measures the temperature of the body as 25˚C while the room temperature is 22˚C. One hour later, the body's temperature is 24˚C. Normal body temperature is 37˚C. The CSI is able to calculate that the crime occurred 3 hours previously. How is this done?
A model of this can easily be set up in the classroom with a beaker of luke-warm water representing the body. The class are challenged to find out when the body 'died', i.e. when did the water have a temperature of 37˚C?
There are more details about this activity in Capturing Data: Modelling and Interpretation, one of a series of booklets presenting STEM Activities with TI-Nspire, published by Texas Instruments in April 2010.