Heat and Heat Transfer
Q4.What is a thermocouple?
Q5.What occurs if a thermocouple is in a complete circuit?
Section 2.
Explain using a diagram how you would carry out an
experiment to plot the calibration curve of a thermometer using
the Laboratory mercury thermometer as a standard.
Section 3.
Q1.Why does heat capacity matter?
Q2.Some cooks make toffee. Essentially, this is a process of boiling down a sugar solution to concentrate it and then allowing the liquid to cool until it sets. Small children are usually warned not to touch the cooling toffee for a very long time – much longer than the cooling for the same volume of pure water in the same vessel. Why is the cooling period so long?
Q3.Why is water commonly used in the cooling system of a motor car? Why is the system pressurised?
Q4.Find out which materials are used as coolants in nuclear reactors. What do these materials have in common?
Q5. What is meant by U value?
Section4.
Q1. Name the three ways in which heat can be transferred from one place to another.
Explain the nature of the movement in each of the transfer methods you have mentioned.
Q2. The solar constant for Ireland is 1500 watts per meter squared. How much energy falls on an area of 2 meters squared in an hour?
If you had solar panels which were 25 percent efficient covering the 2 square meters of ground. How much useful energy would you collect in the same hour?
Q3. Define the following terms.
Specific heat capacity.
Specific latent heat of fusion.
Temperature.
Q4. how much heat energy has been put into a water filled copper calorimeter if 100g of water in the calorimeter of mass 85g is heated from 10 to 25 degrees Celsius?
If this temperature change happens in one minute what is the amount of power going into the system?
Section 5.
The specific heat capacity of water is 4200 J kg–1 K–1; the specific heat capacity of air is about 1000 J kg–1 K–1.
SHC fusion of ice : 3.3X105 j/kg/k SHC vaporisation water 2.3 X 106 j/kg/k
Q1. Estimate how much energy is required to heat the air in your physics laboratory which has
dimensions 3m X10m X10m from a chilly 10 °C to a more comfortable 20 °C. There is one kg of air per cubic meter.
Q2. .If a copper kettle of mass 650g is rated at 2.5 Kw how long will it take to heat 2.25 litres of water from 13 degrees ocelcius to steam?
Q5. If a 50g piece of copper @ 95 degrees is added to 100g of water at 20 degrees what will the final temperature of the system be if there has been no heat lost to the surroundings.
Q6.If a 250g of water @ 98 degrees is added to a 500g piece of water @ 20 degrees, what will the final temperature of the mixture be if there has been no heat lost to the surrounding space.
Q7. How much heat energy is required to take 5g of steam @ 120 degrees to water @ 10 degrees?