Investigating factors which affect heat loss from a beaker of hot water.
Extracts from this document...
Introduction
Investigating factors which affect heat loss from a beaker of hot water Planning In this investigation I am going to survey the factors that affect heat loss from a beaker filled with 55ml of hot water. This will be done by using a numerous amount of materials. Factors which affect heat loss from a beaker of hot water: - Mass of H2O - Size of beaker - Temperature Difference - Material Colour - Air Pressure - Relative Humidity Forms of heat loss: Radiation This is the loss of energy, in this case heat energy, through the atmosphere via electromagnetic waves. (This gives it the ability to travel through a vacuum, i.e. the sun shining through space to Earth.) When this energy reaches an object it is absorbed by it. The energy absorbed causes particles in the object to vibrate, and so it heats up. The hotter an object is, the more energy it has and therefore more radiation will occur. Also the larger the surface area of an object, the more energy it will radiate. Dull coloured objects radiate more energy than shiny objects. Convection Convection is the expansion of particles when they are heated. When a water is heated, the particles within the substance expand and become less dense that normal. Due to this decrease in density the particles rise through the substance, and at the surface of the water some of the particles evaporate. ...read more.
Middle
- The readings and timings should be constant The following factors will be considered when providing a safe test: - Standing up so if water spills we can move quickly - No running - Pour water carefully - Let beaker cool down Results We first had to take a control so that we could compare it to the other results i.e. leaving the beaker by itself on a bench for 600s. Time/s Temperature/?C 0 80 20 79 40 77 60 76 80 74 100 73 120 71 140 70 160 69 180 68 200 66 220 65 240 64 260 63 280 62 300 61 320 60 340 59 360 58 380 57 400 56.5 420 56 440 55 460 54.5 480 53.5 500 53 520 52.5 540 51.5 560 51 580 50.5 600 50 Time/s Temperature/?C 0 80 20 79 40 78 60 77.5 80 76.5 100 76 120 75.5 140 75 160 74 180 73.5 200 73 220 72.5 240 72 260 71.5 280 71 300 70.5 320 70 340 69.5 360 69 380 68.5 400 68 420 67.5 440 67.5 460 67 480 66.5 500 66 520 66 540 65.5 560 65 580 65 600 64.5 Time/s Temperature/?C 0 80 20 78 40 77 60 76 80 74.5 100 73.5 120 72.5 140 71.5 160 71 180 70 200 69 220 68.5 240 67.5 260 67 280 66 300 65.5 320 65 340 64 360 63.5 380 63 ...read more.
Conclusion
Although foil prevented the most heat loss cotton wool and cork still prevented conduction by having cotton wool between both beakers and by placing a cork underneath the beaker. This means that foil would have a lower U-Value than the other materials because it is a better insulator. After completing all the experiments I can say my prediction was correct. This is because the 3rd experiment finished on 68?C meaning it only lost 12?C in 10 minutes. All the other experiments had lost the more heat meaning this one had the most insulation. I also predicted that the 2nd experiment would lose the most heat. This was correct again as it had the least insulation except for double glazing which still prevented 7.5?C. Anomalies - We should have recorded the room temperature before and after to see if it had an effect on the results. - Should have closed all windows to make sure that no drafts came in. - The cork was not always up right. Improvements There are many ways we could have improved the experiment. Here are a few: - Tested out more materials i.e. black card and foam. - Made the experiment longer - Use lid for the beaker to stop evaporation occurring - Use more beakers We could also repeat the experiment again but take it further and calculate U-Values which then would have enabled us to calculate heat energy lost per second using this equation: Heat energy lost per second = U-value (W/m2�C) x area (m2) x T (�C) Anthony Bashyam ...read more.
This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.
Found what you're looking for?
- Start learning 29% faster today
- 150,000+ documents available
- Just £6.99 a month