Prediction I predict that the best way to keep coffee warm is to have a silver insulator because of what we know on radiation and silver being a poor emitter compared to a plain beaker or a black one. I predicted this because most saucepans are silver because silver is a poor emitter compared to white and black and also silver is shiny which cuts down heat wasted by radiation. Research After making a cup of coffee it loses heat because of the following factor: . Radiation. Evaporation. Conduction.
Convection Radiation The sun radiates heat through empty space in the form of tiny waves. If you absorb any of the Suns radiation, it heats you up. This is why it is sometimes called Heat radiation. Everything gives off some heat radiation.
The hotter it is the more it radiates. A black area absorbs much more radiation than a white surface. Much of the radiation that hits a white surface reflects away. A silver surface is a poor absorber and good reflector. An example of radiation is a saucepan. (A saucepan loses heat with radiation and conduction.
Also it loses heat by convection by air currents rising above the saucepan. ) Evaporation Evaporation works in a similar way to conduction. When the beaker or water is heated the molecules vibrate more at different speeds. Every so often, one molecule will gain a lot more speed than the others and will escape.
When it finally escapes it all its energy with it so less is left behind. Now that there is less energy they are cooler. Conduction This is the only method of heat transfer that happens in opaque solids. In the solid the particles are fixed. When heat is added they start to vibrate one by one banging into their neighbouring particle. This is how heat energy is passed on from one particle to the next Good conductors are metals such as gold, silver and glass.
The Essay on Heat Transfer by Conduction Lab
Vocabulary: Conduction- the passage of energy, particularly heat or electricity, through something Rate of Change- the ratio of the difference in values of a variable during a time period to the length of that time period Calorimeter- an apparatus for measuring the amount of heat given out or taken in during a process such as combustion or change of state. The measurements are often made by ...
A glass beaker can be safety heated on a gauze because a gauze conducts heat away from a flame. Convection This method of heat transfer mainly occurs in liquid and gas. In our experiment the water lost heat by convection because the hot water at the bottom density decrease so it rose to the top and cooled. The slightly cooler water descended towards the bottom creating a circulatory motion Variables To make the experiment a fair test the starting temperature was kept to as near as possible.
We did not change the amount of water used so it would be fair. Same Vary Amount of water Insulator size beaker Safety To make sure that this experiment was safe we were careful pouring the hot water by holding the measuring cylinder with a cloth. Observations In this experiment we will be taking the temperature every one minute up to ten minutes. To make this a fair and accurate test we will be repeating the experiment again. Apparatus. 3 C beaker size 250 ml.
Thermometer. Silver foil. Black paper. Kettle. Sellotape.
Scissors To Test for Radiation Wrap the beaker in silver foil and black paper and plain and see what is the best insulator. See what dye is the best yellow or black Method. Set up apparatus as shown with a thermometer inside it… Heat up the water and pour into the beaker… Quickly take the temperature every minute up to ten minutes and record in the results.
Results Table for insulators Minutes Black 1 Silver 1 Plain 1 Black 2 Silver 2 Plain 2 Black 3 Silver 3 Plain 3 0 85 86 85 84 83 82 75 78 73 1 73 75 72 72 74 73 70 71 71 2 70 73 69 70 72 71 68 69 68 3 68 71 67 67 70 62 66 67 66 4 65 68 66 65 67 61 65 65 63 5 64 67 63 64 66 60 63 64 61 6 62 66 61 62 64 60 62 63 59 7 61 64 59 61 63 59 60 61 59 8 60 62 58 58 61 57 59 60 58 9 59 61 57 58 60 55 58 59 56 10 58 60 55 57 58 54 57 58 53 Result table for dye Minutes Yellow Dye 1 Black Dye 1 Yellow Dye 2 Black Dye 2 0 82 85 75 74 1 77 74 68 64 2 74 71 67 63 3 71 68 65 61 4 69 66 64 60 5 67 64 62 59 6 66 62 61 57 7 64 60 59 55 8 63 59 57. 5 54 9 62 57 56 52 10 60 56 55 52 The starting temperatures are starting at different temperatures, which make the graph unfair. So I need to work out the temperature change so I can plot an accurate graph. Minutes Average Black Average Change In Black Average Plain Average Change In Plain Average Silver Average Change In Silver 0 81 0 80 0 82 0 1 72 9 72 9 73 9 2 69 12 70 10 71 11 3 67 14 65 15 69 13 4 65 16 63 17 67 15 5 64 17 61 19 66 16 6 62 19 60 20 64 18 7 61 20 59 21 63 19 8 59 22 58 22 61 21 9 58 23 56 24 60 22 10 57 24 54 26 59 23 Minutes Average Yellow Dye Average Change In Yellow Dye Average Black Dye Average Change In Black Dye 0 79 0 80 0 1 73 6 69 11 2 71 8 67 13 3 68 11 65 15 4 67 12 63 17 5 65 14 62 18 6 64 15 60 20 7 62 17 58 22 8 60 19 57 23 9 59 20 55 25 10 58 21 54 26 Conclusion My prediction was right silver is the best insulator. I know this because at ten minutes silver has not had such a big temperature change compared to the others. We know that heat is being lost because of the graph temperature change is increasing as the time is increasing.
The Essay on Black Suit Man Eli Change
"Eli, The Fanatic" is a short story about a young lawyer dealing with ethical issues in his community. He is torn apart in his decision of choosing between a 'man in a lawyer's suit' and his neighborhood. We find that Eli is trapped in between two conflicting cultures. He, himself has assimilated with his Protestant neighbors and wishes that the Jewish man in the old, black suit would do the same. ...
Evaluation I think that during this experiment we use our apparatus accurately by having the same size beaker and measuring cylinder. I think that our experiment wasnt extremely accurate because of the cooling down at the start. This caused different starting temperature but because the table and graph recorded the change it didnt affect too much. In my graph it shows that Silver is the best followed by black and plain last.
On the other further experiment it showed that yellow dye was better than black dye. I thought that my experiment went well but that human error must have been caused because it was difficult at one time because of measuring and recording all of them at the same time this showed in my plain line where the circled point didnt fit in.
The Research paper on Left-handedness and Experiment
... What is the purpose of a control in an experiment? Does every experiment require a control? Answer: The purpose of a control ... follow-up experimentation might be of use, based on this experiment? Answer: One follow-up experimentation might be our inheritance. ... exercise. Discussion: Propose a hypothesis for a hypothetical experiment and outline the experiment that would be conducted to test it. Use ...
