Investigation of the Cooling of a Liquid in Cups with Different Materials
Aim: To investigate how a liquid cools down in cups with different
materials.
Prediction: The factors which will affect the amount of heat loss are:
§ Material of the cup – Conduction
§ Colour – Radiation
§ Surface area of cup
§ Amount of water (surface area:volume ratio)
§ If the cup has a lid or not – Convection and Evaporation
§ Room temperature
§ Thickness of the cup
§ Temperature of the liquid
§ Air movements – Convection/Evaporation
I will be investigating the material of the cup. I experimented with
four cups. These are metal, polystyrene, ceramic and plastic cups. I
predict that the metal cup will cool down the quickest and the
polystyrene cup will cool down the slowest. I think the ceramic cup
will cool down second slowest and the plastic cup will cool second
fastest.
Reasons: I think that the metal cup will cool down the quickest
because metal is a good conductor. This will mean the metal will
conduct the heat from the water to the outside surface of the metal
and from that point the heat evaporates and goes into the air. I think
that the polystyrene cup will cool down the slowest because it has
pockets of air and air is a good insulator. This will mean that the
heat will stay in the cup and can only escape by rising to the surface
of the water using convection and then it goes by evaporating. I think
the ceramic cup will cool down second slowest because it has some air
particles in it but not as much as the polystyrene cup so it will cool
down a little faster than the polystyrene cup. I think the plastic cup
will cool down second fastest because plastic is a better conductor
than ceramic and polystyrene but not as good as metal.
[IMAGE][IMAGE][IMAGE][IMAGE]Diagram: Metal Cup
Thermodynamics is essentially how heat energy transfers from one substance to another. In “Joe Science vs. the Water Heater,” the temperature of water in a water heater must be found without measuring the water directly from the water heater. This problem was translated to the lab by providing heated water, fish bowl thermometers, styrofoam cups, and all other instruments found in the lab. The thermometer only reaches 45 degrees celsius; therefore, thermodynamic equations need to be applied in order to find the original temperature of the hot water. We also had access to deionized water that was approximately room temperature.
Lab 4: Energy Conservation: Hot Stuff!! The purpose of this experiment is to try to find the original temperature of the hot water in the heater using the 60 degrees C thermometer. Use your 60°C thermometer, and any materials available in your laboratory, to determine the temperature of the water in the coffee pot. During this experiment we calculated the original temperature of a heater after it had been cooled down, and we did this by measuring hot, cold, and warm water, with a thermometer that had tape covering 60 degrees and up.
An Investigation Into How the Thickness of Insulation Affects the Time a Drink Takes to Cool Down
After the calorimeter constant is found we can move on to part two of the experiment, where we will test each of the four salts in the calorimeter to find out if the salt will be used for a hot or cold pack. Our goal is to first determine the q_dissolution and then to find the heat of dissolution. A -〖∆H〗_dissolution will be an exothermic reaction which indicates that the salt would go in a hot pack. While a 〖∆H〗_dissolution will be an endothermic which indicates that the salt would go in an ice pack.
Hypothesis- If we use the felt material to insulate the cup, then the hot beverage in the cup would stay warm longer than the others.
The purpose of this experiment was to see how much the time spent baking in an oven would effect a cupcake. More specifically, how much it effects the rise. Also I wanted to see if I could find the perfect bake time where they tasted the best in my opinion. I was able to do that quite easily, with only a few problems.
Convection is a transfer of internal energy into or out of an object by the physical movement of a surrounding fluid that transfers the internal energy along with its mass. According to Oxford Dictionary, convection is the movement caused within a fluid by the tendency of hotter and therefore less dense material to rise, and colder or denser material to sink under gravity's influence, that results in transfer of heat. Two fluids are liquid and gas.The fluid above a hot surface expands, becomes less dense, and rises.This applies to objects such as steam from a hot cup of coffee turning cool, ice melting like heat moving to ice from the air, or frozen material becoming raw like how frozen food thaws more quickly under cold running water. When
water has had equal amounts of time for it to heat up, again I will
Obtain a sample of metal that has been immersed in boiling water and place it in the cup of water.
Investigation of how Changing the Volume of Water in a Container Affects Its Rate of Heat Loss
Capillary action can only occur when the adhesive forces are stronger than the cohesive forces, which creates surface tension in liquid. The kinetic energy produced when the liquid is heated, allows the attractive forces between the molecules to weaken and this causes them to move past each other more freely. This results in the liquid flowing more easily. Therefore temperature increases capillary action and capillary flow because of the decrease in cohesive force. The intermolecular forces between the molecules are less packed due to the increase in temperature and the surface tension in the liquid will decrease as the temperature increases and this will help the flow of the liquid through the capillary tube.
that the rate of reaction must be fast enough to make as much of the
...top spinning. heat can go through superfluids at a tremendous rate, in fact scientists have reason to believe that in the center of the neutron stars that remain after a super nova could be found superfluid conducting heat away and cooling the star rapidly.
Objects that are not the same size but have the same surface area to volume ratios loose heat at the same rate. So a flask, with a volume of 200cm3 with a surface area of 160cm2 and a surface area to volume ratio of 1.25:1, will loose heat at the same rate as a similar flask of volume 625 and a surface area of 500 which also has a surface area to volume ratio of 1.25:1. However, generally when you increase the size of an object the surface area to volume ratio decreases so in this example it is very likely that the two flasks in question are different shapes.
As discussed in class, submission of your solutions to this exam will indicate that you have not communicated with others concerning this exam. You may use reference texts and other information at your disposal. Do all problems separately on clean white standard 8.5” X 11” photocopier paper (no notebook paper or scratch paper). Write on only one side of the paper (I don’t do double sided). Staple the entire solution set in the upper left hand corner (no binders or clips). Don’t turn in pages where you have scratched out or erased excessively, re-write the pages cleanly and neatly. All problems are equally weighted. Assume we are working with “normal” pressures and temperatures with ideal gases unless noted otherwise. Make sure you list all assumptions that you use (symmetry, isotropy, binomial expansion, etc.).