Question

85 kj of heat is supplied to a closed system at constant volume.During the next process, the system rejects 90kj of heat at constant pressure while 20kj of work is done on it. The system is brought to the original state by an adiabatic process. The initial internal energy is 100kj. Then the quantity of work transfer during the process is?

Answer 1

Answer:

Given heat supplied to a closed system at constant volume is=85kj

The system heat rejects is=90kj

In constant pressure process=20kj

Quantity of work transfer during process=Initial internal energy-system rejected energy

=100-85

=15kj

Answer 2

Answer:

15 kJ.

Explanation:

When the closed system is supplied with a heat of 85 kJ and then the system rejects 90 kJ of the heat when it is in a constant pressure and the work done is 20 kJ.

So, we know that the work done when the system is doing the work will be given as internal energy - heat. So, when the pressure is constant the work is 0 So, u1-u2 is q which is 100-u2=90 which on solving u2 is 10kJ. So, the work done is (90+10)-85 which is 15 kJ.