Evs Lab on Greenhouse Effect

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EVS LAB 1
AIM – To investigate how the greenhouse effect operates.
SAFETY PRECAUTIONS-
* Do not touch the light bulb as it would be hot.
* Handle all equipment carefully, especially the thermometers and the test tubes- as these can break. VARIABLES:-
INDEPENDENT VARIABLES:
* Time intervals between each reading

DEPENDANT VARIABLES:
* Temperature readings
CONTROL VARIABLES:-
* Distance of one bulb to another
* Height of each bulb from surface
APPARATUS
* 2 thermometers (mercury)
* 1 test tube
* Clamp stand
* Stopwatch
METHOD

* Firstly set up the apparatus as shown below

* Make sure the distance and the height between the thermometers are kept the same. * Switch the bulb on. At the same start your stop watch. Make sure you keep distance from the bulb as it could be hot. * After 3 minutes , check the temperature readings in both the thermometers and record it in your raw data table. * Keep doing this till you have 10-15 readings.

* Turn off the bulb
DATA COLLECTION
Reading Number| Temperature (Thermometer with test tube )/| Temperature (Thermometer without test tube) /| 1| 25.2| 24|
2| 25.2| 24|
3| 25.5| 23.5|
4| 25.6| 24|
5| 26| 24.3|
6| 26.3| 25|
7| 26.8| 25.4|
8| 26.8| 25.7|
9| 27.2| 26|
10| 27.2| 26|

Analysis
About 30 percent of the sunlight that beams toward Earth is deflected by the outer atmosphere and scattered back into space. The rest reaches the planet's surface and is reflected upward again as a type of slow-moving energy called infrared radiation. Heat travels due to radiation and hetas up both the thermometers. But the one inside the testtube gets heated more consistently. This happens because there is air trapped inside the testtube which acts as a heat store. As the air molecules get heated, they absorb the heat and then slowly give it out in all directions as well. in the cas of the thermometer which is out in the...
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