Hot Water, Cold Water...
Anybody Need Any Ice?
Introduction
Have you ever had to wait before a hot beverage is cool enough to drink?
Chances are, you’ve experienced the effects of temperature differences,
but have you ever measured temperature in a scientific way and analyzed the
data? In this exercise, we will take a look at these effects and use graphs to
learn more about its behavior.
Background & Overview
Temperature is related to how much internal energy a material contains. The
more internal energy present, the higher the temperature. However, if
there is a difference in temperature between to or more materials, then the
energy will move from the area of higher temperature to the lower
temperature.
Today we will be looking at a few different scenarios:
1.
2.
3.
4.
Ice cold fresh water warming to room temperature in a plastic cup.
Ice cold fresh water warming to room temperature in a foam cup.
Hot fresh water cooling to room temperature in a plastic cup.
Hot fresh water cooling to room temperature in a foam cup.
For each scenario, we will measure the temperature every 3 minutes for a
half hour. We will be dividing into groups, with each group looking at one of
the different scenarios. After we finish, we will plot the data on a graph,
and use the resulting curve to interpret the behavior of the water.
Before you begin: For your scenario, think about what is going to happen. As
a group, discuss the scenario and form a hypothesis about what you think
your final graph will look like. Keep in mind what questions you might be able
to answer with exact information about what temperature the water is at
specific times.
Procedure
1. Before you begin, write down the temperature reading of the
thermometer with the label “Room Temperature.” This is the
temperature of the surrounding air.
2. Prepare a two-column table for recording your data. Label the leftside column “Time” and fill it in with numbers from 0 to 30 in multiples
of 3. This represents the time elapsed, in minutes, of each
temperature
measurement.
Label
the
right-side
column
“Temperature.” This is where you will write down your temperature
measurements.
3. Get your cup with water, thermometer, and stirring spoon from your
teacher.
4. Start your timer, place the thermometer into the water, and wait a
moment. Once the temperature reading on the thermometer stops
changing, write it down in the “Temperature” column in the first row,
next to the time value “0.” This is the initial temperature of the
water.
5. Remove the thermometer from the water.
6. Begin stirring the water, and continue to stir until the next
temperature measurement.
7. After 3 minutes, place the thermometer back in the water and take a
new measurement. Write it down, along with the time of the
measurement. Repeat until 30 minutes has passed. When you are
finished, you should have 11 data points, including the initial
temperature.
Analysis
Make a graph of your temperature measurements, putting time on the x-axis
and temperature on the y-axis. Connect the data points and interpret the
results. Was your hypothesis supported by the data? Did the temperature
of the water ever equal that of the surrounding air? Is the data linear or
nonlinear? What is the independent variable in this exercise? What is the
dependent variable?
© 2010 John Bush, Colorado School of Mines GK-12 Learning Partnership, http://inside.mines.edu/~jobush/gk12
Support for this work is provided by the National Science Foundation’s Graduate Education, NSF, DGE-0638719
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free
Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no
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