Equipment:
This is a list of all the apparatus I will need to use to investigate my variable.
300ml Beaker: to contain the volume of H2O.
Kettle : To heat up the H2O.
Thermometer: To measure the temperature of the H2O.
Stopwatch: To time the temperature of each volume of H2O every 30sec.
H2O : To investigate the rate of cooling.
Diagram: This diagram shows the format and layout of my experiment:
Plan:
- Collect Equipment needed for investigation.
- Boil the water using the kettle.
- Fill the beaker with the correct volume of water, then immediately insert the thermometer into the beaker with the boiling water. Remembering for safety reasons do not sit down while doing the experiment.
- Start the stop watch immediately not forgetting to record the starting temperature. Take a reading from the thermometer every 30seconds, remembering to record results in a table.
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Repeat this until all volumes of H2O has been investigated, but still using the same beaker for the next amount of water so it will be a fair test.
- A few pointers of fair testing:
- Remember to make sure that the thermometer is upright so you can take an accurate reading.
- Make sure the Bulb of the thermometer is covered in the boiling water.
- Make sure when investigating a different volume of water you get the thermometer back to the same starting temperatures as the previous volumes.
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This is How I will display and record my results:
Analysis
Trends and patterns:
The 100ml line, the 150ml line and the 200ml line have approximately 4 degrees difference from 240seconds into the experiment .This is because convection is happening relatively at the same time for each one.
On my graph of just 50ml, there is at least three obvious points of temperature change these are marked on the graph. This is because they are the points when convection seems to slow down concluding that the temperature id cooling down. This theory is shown in my prediction and all the information plotted on my graph shows that my prediction was correct to my results.
Evaluation:
My results are accurate because we did everything that we could to ensure this was a fair test. My results show that the more water there is there longer its takes to cool down this is due to convection which is when
The hotter particles get somewhere cooler they then transfer their energy by the usual process of collisions which takes over the cool particles and warms up the surrounding.
The results are reliable because they fit in with the laws of Issac Newton, which is that the rate of change of temperature of some body is proportional to the temperature difference of that body to its surroundings. Another way to say the same thing is that the rate of heat transfer through a substance is proportional to the difference in temperature across the substance. They are not odd results they do fit in with the pattern this is shown on my graph.
I could improve my plan by maybe having two or three variables these would make my investigation more detailed and perciffic.I could check this trend/patern by making another graph with just a single line of a water volume to show at which point does convection start to fade at.
The next experiment I could do to proive my varaible would be if I did the same experiment but actully covered the top of the beaker to prevent evapouration, to see which volume took the longest to cool down.