Stuck again, problem- A cup of coffee cooled from 96 degrees C to 65 degrees C after 8 min. in a room at 20 degrees C. When will it cool to 25 degrees C?

Question

directrix · Answer

I like this statement of Newton's Law of Cooling. Maybe we can use it.

directrix · Answer

We need to pair the given information to the variables in the equation.

directrix · Answer

This equation is the one I'm using to solve for k. The time is in minutes. 65 = 20 + (96 - 20)*e^(-8k) k is approximately .066 http://www.wolframalpha.com/input/?i=65+%3D+20+%2B+%2896+-+20%29*e%5E%28-8k%29

directrix · Answer

T(25) = 20 + ( 25 - 20 ) + (25 - 20)*e^(-t*(.066)) I'm getting that after* t = 15.2 minutes*, the coffee temperature will be 25. I hope somebody will come along and check this because I am not sure of that answer. http://www.wolframalpha.com/input/?i=+20+%2B+%28+25+-+20+%29+%2B+%2825+-+20%29*e%5E%28-t*%28.066%29%29+%3D @marie.serina09