Please answer a) and b) correctly

Question

A thermometer is taken from a room where the temperature is  to the outdoors, where the temperature is . After one minute the thermometer reads .



(a) What will the reading on the thermometer be after  more minutes?

(b) When will the thermometer read ?

__________________ minutes after it was taken to the outdoors.

Answer 1

The equation for heat loss presumably is

dT/dt = -k(T-2)

dT/(T-2) = -kt and the solution is

T = 2+Ce^-kt where C and k are to be determined from the initial conditions.

You should be able to determine C and k to solve the problem completely.

T=temperature, t=time.

When t=0, T=21 and when t=1, T=16.

Plug these values pairs into the equation for T and get a pair of simultaneous equations which you can solve for k and C. This will allow you to evaluate T for any other value of t.