To see how long it takes the size of a hot object to cool down Essay
Planning: I will make sure I devise a fair test by doing things correctly and fairly. The only variable I will be obtaining will be the temperature of the water at 80oc, and I will make sure it is fair by testing it with a thermometer. I will also make sure it is a fair test by adding more water into the bigger beakers because it wont all fit into the smaller ones so that will give the smaller beakers a fair chance as well, and I will measure the water in a measuring cylinder to make it fair.I will also make sure I devise a fair test by using a stopwatch to record the result every 30 seconds up to 2minutes, because it is more reliable and accurate. I will make sure it is fair when we record the results because when we get the temperature I will get a second opinion of my friend. I will also make sure my experiment is safe in all the possible ways I can. I will make sure we are safe by wearing rubber gloves just in case we spill some boiling water on our hands.Prediction: I predict that the bigger the beaker the faster it will cool, and the smaller the beaker the longer it will take to cool. I know this because of the “Food Theory”, the theory tells me that if there was a plate with a pile of hot food on it, it will take quite long for it to cool down, where as if you were to break that pile of hot food into smaller pieces of food then it will cool down much quicker because when you break it up you are giving it a bigger surface area so heat can escape around the sides, top and bottom. So therefore I think the same will happen with the beakers, but the bigger the beaker is obviously going to have a bigger surface area than the smaller beakers, where as in the theory the smaller food pieces have a bigger surface area than the pile of food, but that is because you cant break the beakers into pieces.Apparatus:* 4 different sized beakers* Water at 80oc* Kettle* Thermometer* Rubber Gloves* Stop watch* Pen & Paper (for results)Method: First of all I got the equipment, which consists of 4 different sized beakers, a thermometer, a kettle, measuring cylinder and some water. Then I put the kettle on, when the water was boiled up to 80oc I measured it in the measuring cylinder and put the correct amount of water into the correct beaker, then we waited and every 30 seconds on the stop watch, we then measured the temperature of the water in the 4 beakers with a thermometer, then we recorded them on paper and plotted some graphs.Numbers and range: In total I will have 4 results for the 4 different sized beakers and for each beaker I will have two readings, and I will record the results every 30 seconds and at the end of all the results I will take away 2 minutes from 0 seconds for the first reading of the first beaker then I will do the same to the second reading for the first beaker then I will add them both and divide them by two which will give me an overall average for the first beaker, and I will carry that on for the next 3 beakers, in the end I should end up with 4 different averages with which I will plot a graph. Here are the 4 different beakers:BEAKER 1: The biggest with 150ml of waterBEAKER 2: The second biggest with 100ml of waterBEAKER 3: The third biggest with 75ml of waterBEAKER 4: The fourth biggest with 50ml of waterSafety: I will try and make my experiment safe by firstly wearing rubber gloves in case we spill the boiling water, secondly by consulting a teacher before and after we set up the experiment.CONCLUSIONCalculation: I calculated my averages by working out the difference between 2 minutes and 0 seconds for the first beaker and the first reading, then I did the first beaker and second reading, I then added the sums together and divided them by 2, to give me an average. I did this for the 3 other beakers as well. So I ended up with 4 overall averages.Pattern: I would say that a pattern did occur in both of my graphs, as you can see in the graphs labelled ‘result 1’ and ‘result 2’all the lines go from a high temperature to a low one which shows that the temperatures did drop after some time, which was meant to happen, but then you see on graph ‘result 1’ the order from top to bottom is: beaker 1, beaker 4, beaker 2, beaker 3, which proves my prediction wrong about the bigger the beaker the faster it will cool, because beaker 4 is the smallest beaker and it cooled down faster than beaker 2 and 3, and also it starts off with beaker 1 which it should have, then it jumps straight to beaker4 which should be last, but then it carry’s on as normal; beaker 2 and then beaker 3, so I think there was a problem within beaker 4. In the graph ‘result 2’ you can see the order from top to bottom is: beaker 3, beaker 1, beaker 2, beaker 4, so beaker 3 should be third but you can see that the rest is in order, so beaker 1, beaker 2, then it should have been beaker 3, then beaker 4, so I think there was a problem within beaker 3. In the graph labelled ‘averages’ I think it all goes pear shaped, because the points are so far apart from each other, which made it harder for me to draw the line of best fit, you can also see the averages in order from highest temperature to lowest temperature is: beaker 2, beaker 4, beaker 1, beaker 3, so I think that because the averages have turned out like that and not how I expected which was beaker 1,2,3 and then 4, I think that the whole experiment must have went wrong from start to end.Evaluation: In my experiment I found that most of my results were quite off key, in the graphs ‘result 1’ and ‘result 2’ the orders were only one out of order. Then when it came to the graph labelled ‘averages’ the order was completely wrong to what I predicted, I predicted the bigger the beaker the faster it will cool, if that happened the order would have been beaker 1, 2, 3, and then 4, but because it went wrong it turned out beaker 2, 4, 1 and then 3. if you look at the graph ‘result 1’ the problem was beaker 4, and in the graph ‘result 2’ the problem was beaker 3, I don’t have a clue why those problems occurred, and by looking at the average I think I could have improved my experiment by doing it all over again but much more carefully this time round.