Experiment 8: Radiometer

date | aim | method | materials & equipment | results | conclusion

Date

9 December 2009 by Quest 2, to link in with Chapter 8 of our book.

Aim

To investigate the effects of sunlight on a Crookes radiometer.

Method

Place a Crookes radiometer in the following locations and observe how fast the blades rotate.

1. A shady place indoors.
    
2. A shady place outdoors.
    
3. A sunny place outdoors.
    
4. A sunny place outdoors, but under a black light-proof cloth. Remove the cloth.

Materials & Equipment

• A Crookes radiometer.

Results/Observations

1. The blades rotated slowly.
    
2. The blades rotated quickly.
    
3. The blades rotated so quickly they were a blur.
    
4. The blades almost stopped completely under the cloth, and started spinning quickly as soon as the cloth was removed.

Conclusion

• A Crookes radiometer is an effective device for getting a rough idea of the intensity of incident light.