# Homework Help: Newton's Law of Cooling

1. Mar 6, 2005

### Physically Impaired

I am stumped on one question out of twenty on my lab report.

T = T0e-kt + Troom

When T = 0 what is the value of e to the negative kt

2. Mar 7, 2005

### so-crates

Do you mean when t = 0 or T = 0? T can never be zero, because e-kt will always be positive.

3. Mar 7, 2005

### HallsofIvy

If t= 0 then T= T0+ Troom

If it is T= 0 then if either T0 or Troom is negative (but not both!) (possible if T is measured in Celcius or Farenheit, impossible if T is measured in Kelvins), solve 0= T0e-kt+ Troom:
$$e^{-kt}= -\frac{Troom}{T0}$$

4. Mar 7, 2005

### dextercioby

Halls,it's Anders Celsius (sic) and Gabriel Fahrenheit (sic)

Daniel.