Thermodynamics: Radiant Heat

Experience may tell you that dark-colored objects absorb radiant heat more quickly than light-colored objects. But is the reverse true?

Do dark-colored objects emit radiant heat more quickly than light colored objects? Determine the relationship between the color of an object and the rate at which it emits energy.

Motion Sensors

The difference in rate of heat loss is dramatically shown. The dark container (green line) transfers the heat energy in the water much more quickly than the unpainted container (red line). Enlarge graph.

Lab Summary:

Students will use Temperature Sensors to determine if there is a relationship between a container's color and the rate at which it loses energy due to radiation.

To accomplish this they will use two temperature sensors to measure and compare the change in temperature of equal amounts of hot water stored in two metal containers (one black and one unpainted) as the water cools over a 15-minute period. By determining which container transfers energy to its environment the quickest, they will draw conclusions about how the color of the container affects the rate of energy transfer.

Download free labs:

(student versions)

Download Free Lab  (PDF, 528 KB)

Xplorer GLX-based lab  (PDF, 2.2 MB)

Method:

Use Temperature Probes to measure the change of temperature of initially hot water as equal quantities of the water cool in two similar aluminum cans.

Motion Sensors

 

Here's What You Need:

Required for computer-based lab:

(See lab download for Xplorer GLX-based lab requirements, which may differ)

Probeware

Other Materials

Lab Manual:

The computer-based activity is included in Explorations in Physics (PS-2810) . The Xplorer GLX-based lab is included in Physics with the Xplorer GLX (PS-2826). Both manuals are complete with Teacher Information pages, student instructions and handouts, and sample data.

For your convenience, we offer bundles which provide the probeware for the activities in the manual. For more, please see:
Computer-based Physics Lab Manual and Bundles
Xplorer GLX-based Physics Lab Manual and Bundles