The Case of the Murdered Accountant
A coroner uses a formula derived from
Newton's Law of Cooling, a general cooling principle, to
calculate the elapsed time since a person has died.
The formula is
where T = the body's measured temperature (Fº)
Rt = the constant room temperature
t = is the elapsed time in hours since death
A more accurate estimate of the time of
death is found by taking two readings
and averaging the two calculated times of death.
After a busy evening
of income calculations an accountant was found dead
in his office. At 10 a.m. the coroner measured
the body temperature to be 85.6º F. A second
reading measured at noon found the body temperature
to be 82.6º F. Assume the room was a constant
According to the
coroner what would be the estimated time of death of
the accountant to the nearest minute?