Molecular Physics | Thermodynamics Answers

A carnot refrigerator takes heat from water at 0 C and rejects heat to a room at 27C. If 50 kg of water at 0C is converted to ice at 0C, how much energy must be supplied to the refrigerator?

the diagram shows a mercury glass thermometer containing nitrogen,, graduated on the Kelvin or absolute scale. bp. = 633K, mp.= 230K, softening point of glass= 750K
a) give the reason why why the scale need not to be graduated below the mark 200
b) give oine advantage of hvin nitrogen in the tube rather than vaccum.
c) give a reason why the scale is not graduated above the 700 mark.

who was responsible for the discovery of geoyhermal energy in the country?

How much weight can be lifted by a Hydrogen (& also separately for Helium) filled balloon of 10 cubic Meter, at sea level & at a temp. of 20 Degree Centigrade. Pl. describe the inputs used.

The temperature of an electronic oven is 167.3°C. The temperature at the outer surface of the oven in the kitchen is 48.8 °C. The oven (surface area = 1.7 m2) is insulated with material that has a thickness of 0.02 m and a thermal conductivity of 0.04 J/(s m C°). How much energy in Joules will be used to operate the oven over 3 hours?

how many kilojules are in calories?

1kg of water at 273K is brought in contact with a heat reservoir at 373K
1-What is the change in entropy of water when temp reaches 373K
2-what is change in entropy of
the reservoir
the universe

A spark-ignition engine operates on an Otto cycle with a compression ratio of 9 and temperature limits of 30 degrees C and 1000 degrees C. If the power output is 500 kw, calculate the thermal efficiency and the mass flux of air. (Answers: 58.5%, 2.19 kg/s -- Solution steps needed!!)
TEXTBOOK: Schaum's Thermodynamics for Engineers (Second Edition)

A curved metal mirror with a surface area of 1.2 metre square focuses the heat energy from the sun on to a small tank containing water.Assuming that the average amount of energy received from the sun at the mirror, per square metre, is 550J, calculate the minimum time needed to increase the temperature of 5 Kg of water from 20 degrees celcius to 100 degrees celcius, given that the energy needed to increase the tempertature of 1 Kg of water by 1 degree celcius is 4200J.

On which height could you lift a car of mass (m=800kg) if you would completely use the energy from cooling 1kg of water from temperature of 30 degrees Celsius to 20 degrees Celsius? Specific heat capacity of water is: c=4,186*10^3 J/kgK? (It is also given that the correct answer is 5m)