Explore BrainMass

Newton's Law of Cooling

Case: At 9:00 PM a coroner arrived at a hotel room of a murder victim. The temp. of the room was 70 degrees F. It was assumed that the victim had a body temp. of 98.6 degrees F (AT THE TIME OF DEATH)(not at 9:00PM). The coroner took the victim's temp. at 9:15 PM at which it was 83.6 degrees F and again at 10:00 PM at which it was 80.3 degrees F.
A. At what time did the victim die? I solved that question to be at 7:15 PM (165 min before 10:00PM)
B. If the assumption of the victim's body temp. at the time of death was found to be incorrect due to a major outbreak of influenza at the hotel during the victim's stay and the usual fever a flu case will run is 103 degrees F. What is the time of death then? I solved it to be 6:37 PM(203 min before 10:00PM).
C. If the victim had no influenza at the time of death, but the room temp was really 75 degrees F what was the time of death then? answer was 7:47PM(133 min before 10:00PM)
D. Assuming the victim was murdered 3 minutes of the time the murderer got off the elevator(which had video surveillance) what five minute sequence should have been reviewed in each scenarios a, b, and, c?

Solution Preview

Please see the attached file.

Newton's Law of Cooling describes the cooling of a warmer object to the cooler temperature of the environment. Specifically we write this law as,
T (t) = Te + (T0 − Te ) e - kt (1)
where T (t) is the temperature of the object at time t, Te is the constant temperature of the environment, T0 is the initial temperature of the object, and k is a constant that depends on the material properties of the object.
1. In this case: Te ...

Solution Summary

The solution provides detailed analysis, theory and discussion for the Newton's Law of Cooling word problem.