APPARATUS REQUIRED:
Three beakers of different volume and different sizes, water, thermometer, stop watch, burner, measuring cylinder.
VARIABLES
RAW DATA:
Least count of thermometer: 1 Uncertainty of thermometer:
The initial volume of water taken in each beaker was 80ml and for each of the three cooling cases the initial temperature of water was taken to be 60. The table shows the fall in temperature of water in the three beakers over a period of ten minutes.
Graph for the fall in temperature in the first beaker over a period of time.
This is the graph of the fall in temperature of water when it is kept in the first beaker. We can clearly notice that the temperature falls very slowly while the water is kept in this beaker.
Graph of fall in temperature in the second beaker over a period of time.
This graph shows the fall in temperature of water over a period of ten minutes while kept in the second beaker. This graph clearly states that the water cools faster than in the first beaker.
Graph of fall in temperature in the third beaker over a period of time.
The above graph shows the fall of temperature in water over a period of ten minutes while it is in the third beaker. We can see that the water cools faster in this beaker than in the other two.
CONCLUSION:
The beakers used in the experiment all had different surface areas. The 1st beaker had the smallest surface area, the 2nd beaker had a surface area bigger than the first one and the 3rd beaker had the largest surface area. From the data given above in the above depicted graph, we can infer that:
- The cooling of water was fastest in the third beaker.
- Since the surrounding temperature was constant, the reason for different cooling rates was not the difference in ambient temperature.
- The water in the beaker with the largest surface area cooled the fastest.
- Therefore, as the surface area increases, so does the heat loss.
EVALUATION:
Possible sources of error
- There was a deep dive in the readings for the third beaker for a minute which might have been due to the fan being on or due to wind blowing in through the open window.
- These could be possible sources for any other errors too.
- Also the fault in the readings could be due to a human error.
- The fall in temperature might not have been very steady due to the change in the surrounding temperature.
Possible areas for improvement
- The fan should not be on while the experiment is being conducted and their should be no other form of air flow.
Candidate name: Shwetank Rastogi
Candidate session number:
