Molecular Physics | Thermodynamics Answers

How much oil at 200 degrees Celsiusmust be added to 50g of the same oil at 20 degrees celsius to heat it to 70 degrees celsius

What are the various gas laws ? Elaborate them . What is the application of gas laws in anesthesia practice ?

If 5L of a gas is at 1.08 atm . Supposing the volume was 10L what will the volume be at a standard temperature

Imagine that a fridge has dimensions 1m by 1m by 1.9 m tall and insulated walls of 20.0cm thickness ( single layer K=0.15) . If the room is at 20°C and we set the inside temperature to 4°C then find a) the rate of thermal energy transfer b) the electric energy it uses if it has COP 1.75 c) heat energy created by fridge

An object floats in water on a planet with 10% of the object outside the water. If the container containing water falls freely , then the percentage of volume of the object inside the water is:

(a)10% (b)<10% (c)<90% (d)90%

A Carnot refrigerator is operated between two heat reservoirs at temperatures of 320 K

and 270 K.

• If in each cycle the refrigerator receives 415 J of heat energy from the reservoir at 270 K, how many joules of heat energy does it deliver to the reservoir at 320 K?
• If the refrigerator completes 165 cycles each minute, what power input is required to operate it?
• What is the coefficient of performance of the refrigerator?

1. A typical student listening attentively to a physics lecture class has a heat output of 100 W. How much heat energy does a class of 90 physics students release into a lecture hall over the course of a 50-min lecture?
2. Assume that all the heat energy in part 1 is transferred to the 3200 m³ of air in the room. The air has a specific heat capacity of 1020 J/kg-K and a density of 1.20 kg/m³. If none of the heat escapes and the air conditioning system is off, how much will the temperature of the air in the room rise during the 50-min lecture?
3. If the class is taking an exam, the heat output per student rises to 280 W. What is the temperature rise during 50 min in this case?

estimate the number of molecules in 1.00m^3 of air by assuming that it has a density of 1.21kg/m^3 and that is entirely composed of nitrogen molecules

In the compression stroke of an internal combustion engine the heat rejected to

the cooling water is 45 KJ/Kg and the work input is 90 KJ/Kg. Calculate the

Change in internal energy of the working fluid stating whether it is a gain or

loss

A car is driving at 25 m/s and sees a red light. The car comes to stop over a distance of 100 m. What is their acceleration? Time?