Thread: Temperature

The late Mac the Knife is found at midnight with a body temperature of 90 degrees F, in a room where the temperature is 70.
At 1 a.m. he has cooled to 80 degrees.

When was he killed? Why?

Can this equation get me to the answer?

Is that all that was given to you? The question seems to be very confusing. Your equation is right but -.01 shouldn't be there btw, you need to use Newton's law of cooling which states that if u is the object then the rate at which it cools is

du/dt = -k(u - T)

-k = constant

T = ambient temperature

Originally Posted by cammywhite

The late Mac the Knife is found at midnight with a body temperature of 90 degrees F, in a room where the temperature is 70.
At 1 a.m. he has cooled to 80 degrees.

When was he killed? Why?

Can this equation get me to the answer?

You need to solve the differential equation (Newton's law of Cooling) given in post #2. Let t = 0 correspond to midnight. Then the boundary conditions for this differential equation are T = 90 degrees F at t = 0 and T = 80 degrees F at t = 1.

You need to find the value of t (it will be negative) when T = 98.9 degrees F (normal temperature of living person).