- #1

- 301

- 0

## Homework Statement

A cup of boiling water is placed outside at 1:00 PM. One minute later the temperature of the water is 152 degrees Fahrenheit. After another minute its temperature is 112 degrees Fahrenheit. Find the outside temperature.

## Homework Equations

None.

## The Attempt at a Solution

T(t)=Ta+(To-Ta)e^(-kt)

T(t)=Ta+(212-Ta)e^(-kt)

T(1)=152=Ta+(212-Ta)e^(-k)

T(2)=112=Ta+(212-Ta)e^(-2k)

152-Ta=(212-Ta)e^(-k)

112-Ta=(212-Ta)e^(-2k)

112/152=e^(-k)

e^k=152/112

k=ln(19/14)

Now I'm stuck. What do I do?