# Thread: tricky DE problem.. heat etc

1. ## tricky DE problem.. heat etc

ok everyone... i have this problem its a bonus for class, im preety sure i have the right answer (1139 valentines day)
here is the problem:: a dead body was found valetines day. in a room with no AC. The daily temperature of the room flucuates according to the function T(t)= 60-10sin (pi*t/12) where t=0 corresponds to midnight on any given day. The body was found at 3:00am feb 15 and the temperature was 78F. 4 hours later the temp was 55F. What is the time of death?

this is how i have set it up
78-55=k(60-10sin(pi*t/12) -78)

correct?

2. Originally Posted by johan
ok everyone... i have this problem its a bonus for class, im preety sure i have the right answer (1139 valentines day)
here is the problem:: a dead body was found valetines day. in a room with no AC. The daily temperature of the room flucuates according to the function T(t)= 60-10sin (pi*t/12) where t=0 corresponds to midnight on any given day. The body was found at 3:00am feb 15 and the temperature was 78F. 4 hours later the temp was 55F. What is the time of death?

this is how i have set it up
78-55=k(60-10sin(pi*t/12) -78)

correct?
see post #8 here for the set up. you have $T_{amb} = 60 - 10 \sin \left( \frac {\pi t}{12} \right)$