Molecular Physics | Thermodynamics Answers

An engine is tested by means of a water brake at 1000 rpm. The measured torque of the engine is 10000 Nm and the water consumption of the brake is 0.5 m3 /s, its inlet temperature being 20°C. 

Calculate the water temperature at exit, assuming that the whole of the engine power is ultimately  transformed into heat which is absorbed by the cooling water.

Air is contained in a piston cylinder arrangement as shown in Fig. The piston can be assumed to be massless, frictionless, and perfectly insulated. 10 kg of dry ice (solid CO2) is placed on top of the piston. The initial conditions for air inside the cylinder are P1=121 kPa, T1= 300 K. Dry ice sublimates gradually, and its mass reduces to 5 kg. Ambient air is always at room temperature (27oC) and atmospheric pressure. (Given: R=287 J/kg ·K, g = 9.8 m/s2 , CP/CV for air = 1.4; Neglect all heat transfer to the dry ice block.)

a) Assuming the cylinder to be perfectly insulated, calculate the specific work done for the process.

b) Assuming the cylinder to be perfectly conducting, what is the heat required per unit mass of air to complete the process?

c) Plot the processes described in (a) and (b) together on a Pv diagram. From this plot, which process appears to have more work? Explain.

A small sample of coal, when completely converted into energy, releases 3.75 * 10 ^ 34j What is the initial mass of coal, assuming the final mass is 0? 

determine the volume, internal energy, enthalpy, entropy and density of 3kg of steam at a pressure of 5mn/m² and with a temperature of 350°c

Radiation intensity of a dipole depends strongly on frequency. If at a frequency f, the intensity of radiation is 'I'. Then at a frequency of f/2, the intensity will be

A broadside array consisting of 200 cm wavelength with 10 half-wave dipole spacing 10 cm. And if each array element feeding with 1 amp. current and operating at same frequency then find the half power beamwidth

What is rotational energy.

What is efficiency of refrigrator.

Explain carnot engine efficiency

What thermodynamic properties are independent of the amount of substance present