IR

IR IMS Radiation Lab:           I.M.S. SCIENCE              Name(s): __________________________

   INVERSE-SQUARE LAW:                                                              Period: ______ Date:`___________  SCORE:____   /20  ___

        CAUTION: DO NOT AIM AT EYES          
     Purpose: The purpose of these labs are to investigate the infrared (IR) region of the electromagnetic spectrum using devices that detect IR sources.

Required Equipment and Supplies: Hot plate, radiometer, pan, or other item to raise hot plate, metric ruler, graph paper, and stopwatch.

Read the article at : http://fusioned.gat.com/education_notebook/images/pdf/EMcurriculum.pdf


    Then answer the Review Questions below:

1. Which regions of the electromagnetic spectrum penetrate the earth's atmosphere completely?

2. Which waves do not penetrate the earths atmosphere?

3. What do all electromagnetic waves have in common?

4. What are three ways you can detect infrared radiation?

5. How can a pit viper tell that a mouse is hiding in a very dark place?

6. Can you see infrared waves? Explain.

Procedure

1. Place hot plate on its side and plug it in. The hot plate must be at approximately the same level as the vanes of the radiometer (place on block or pan).

2. Turn on the hot plate and give it two minutes to warm up.

3. After the hot plate warms up you will be setting the radiometer in front of it about 24 cm away. You are to observe the number of rotations the vanes on the radiometer make in a two-minute period.

4. Move the radiometer to 22 cm observing the number of rotations for another 2 minutes. Continue to move the radiometer in at 2 cm intervals and record for two minutes at each interval. Record the number of rotations on your data table. Repeat this step until you reach 6 cm.

 

 

 

 

 

 

 

6. Record data in table below.


TRIAL

DISTANCE

FROM SOURCE


TIME

NUMBER OF ROTATIONS

1

 

 

 

2

 

 

 

3

 

 

 

4

 

 

 

5

 

 

 

6

 

 

 

7

 

 

 

8

 

 

 

9

 

 

 

10

 

 

 

11

 

 

 

12

 

 

 

13

 

 

 

14

 

 

 

15

 

 

 

Analysis of Experiment

1. Graph the number of rotations and the distance.

2. Did distance affect the radiometer's rotation?

3. What mathematical model can you use to predict the results?

4. Explain the journey of the infrared radiation from the moment it leaves the hot plate to the point at which the radiometer begins to rotate.