Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Determining which coffee has a greater rate of cooling

  1. Aug 31, 2011 #1
    Hey,

    I have this math investigation task which asks us to model the cooling of coffee in three different cups over a period of time. Anyway, i got the data, did a scatter plot and found the exponential model, but i dont know how i could determine which one has the greatest rate of cooling.

    I know that I need to look at the slope, but they dont all start from the same point on the graph, so i cant determing which one has the fastest rate of decay. If they all started from the same point i would be able to see the different functions branching off from that point, and if one has a steeper slope than the other i would know, but this wasnt the case. Can someone please help! Thanks.
     
  2. jcsd
  3. Aug 31, 2011 #2

    micromass

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Calculate the slope at a common point. For example, take the point 40° at every coffee and calculate the slope at that point.
     
  4. Aug 31, 2011 #3
    Hey thanks man. Do you know if the relationship of the derivative of the three graphs will change. So if i measure the derivative of each graph at some temperature (remember it's exponential) and find that one graph has a steeper slope than the other... could that change? so the other graph will now have the steeper slope? Because if that is true, then we cant use that to determine which graph has the fastest rate of cooling overall. Thanks.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Determining which coffee has a greater rate of cooling
  1. Cool integral (Replies: 12)

  2. Rate of Change (Replies: 3)

Loading...