- #1
pezgoon
- 7
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I'm going to write this up the same way my teacher gave me the sheet
At 9am on october 19, 2009 a body was found in room 327 at University Center. The room is kept at a constant temperature of 72 degrees. The medical examiner was called and he arrived in eight minutes. The first thing he did was to take the temperature of the body. It was 83 degrees. Thirty minutes later the temperature of the body was taken again and it was now 78 degrees. Help the police by telling them when the person was murdered.
Variables
t= time
y= temp. in degrees Fahrenheit of an object in a room
T= temperature in degrees Fahrenheit of the room
T= 72
yinitial(0)= 98.6 (assumed)
yfirst(t+8?)= 83
ysecond(t+38?)= 78
I put the question marks cause I'm not sure whether that is the right time.
This is the equation as it was given to me
ln|y-T|= kt + C
but everywhere else I look has a different formula than this one the closest i could find/come up with (i can't remember at this point) is
y-T=e^(kt + C)
I have tried the equation (and just about every other one I could find or think of) so many times that I cannot figure them out on the paper anymore and I am basically lost as to where to start because every way I've tried by plugging the numbers back into try and get the temp at the time comes out wrong. Can someone please help?? Thanks to whomever can
Homework Statement
At 9am on october 19, 2009 a body was found in room 327 at University Center. The room is kept at a constant temperature of 72 degrees. The medical examiner was called and he arrived in eight minutes. The first thing he did was to take the temperature of the body. It was 83 degrees. Thirty minutes later the temperature of the body was taken again and it was now 78 degrees. Help the police by telling them when the person was murdered.
Variables
t= time
y= temp. in degrees Fahrenheit of an object in a room
T= temperature in degrees Fahrenheit of the room
T= 72
yinitial(0)= 98.6 (assumed)
yfirst(t+8?)= 83
ysecond(t+38?)= 78
I put the question marks cause I'm not sure whether that is the right time.
Homework Equations
This is the equation as it was given to me
ln|y-T|= kt + C
but everywhere else I look has a different formula than this one the closest i could find/come up with (i can't remember at this point) is
y-T=e^(kt + C)
The Attempt at a Solution
I have tried the equation (and just about every other one I could find or think of) so many times that I cannot figure them out on the paper anymore and I am basically lost as to where to start because every way I've tried by plugging the numbers back into try and get the temp at the time comes out wrong. Can someone please help?? Thanks to whomever can