Molecular Physics | Thermodynamics Answers

Calculate the internal energy and enthalpy of 1 kg of air occupying 0.05m3 at 20 bar. If the internal energy is increased by 120 kJ/kg as air is compressed to 50 bar, calculate the new volume occupied by 1 kg of air. Assume air is a perfect gas

Determine the mass of air in a vacant room whose dimensions are 4m × 5m × 6m at 100 kPa and 25°C.

a bullet fired into a target loses 1/n th of its velocity after penetrating a distance x into the target how far the will it penetrate before it comes to rest express your answer in terms of n and x

Suppose you are wearing a bracelet that is made of unbroken ring of copper wire. I f you walk briskly into a strong magnetic field while wearing the bracelet, how would you hold your wrist with respect to the magnetic field in order to avoid inducing a current in the bracelet?

A wave has a length of 2m and a frequency of 10Hz. Calculate the wave number . Calculate the angular frequency. Calculate wave speed

A block 4kg in mass rests on a horizontal plane. What value of horizontal force is required to (a) move the block, (b) maintain the motion of the block once it is moved? The coefficients of static and kinetic friction are 0.23 and 0.18, respectively. What will the force be, if the force is instead applied 25° above the horizontal?

The pressure and temperature of mixture of 4 kg of O2 and 6 kg of N2 are 4 bar 

and 27°C respectively. For the mixture determine the following ) :i) The mole 

fraction of each component ; (ii) The average molecular weight; (iii) The specific 

gas constant ; (iv) The volume and density ;(v) The partial pressures and partial 

volumes

 90 kJ of heat are supplied to a system at a constant volume. The system rejects 

95 kJ of heat at constant pressure and 18 kJ of work is done on it. The system 

is brought to original state by adiabatic process, i.e. (Heat add or reject of this 

process is equal zero). Determine, (i) The adiabatic work; )ii) The values of 

internal energy at all end states if initial value is 105 kJ. Draw the 

thermodynamic cycle on Pv diagram.

In a vertical frictionless piston and cylinder arrangement, 10 grams of water are 

heated to expand from 5 bar and 200oC to 500oC by a heat reservoir at 600oC. 

Find work and heat exchanged by water during this process. Find entropy 

change of water, heat reservoir and universe.

5. In a turbine, 0.3 kg/s of CO2 expands from 5 bar and 27oC to 1 bar according to 

the polytropic process Pv1.2 = constant, in order to produce cold gases for an 

industrial process. Find the final temperature as well as heat and mechanical 

powers exchanged.