Calculate the internal energy change in each of the following systems.
System I: 10 kJ heat energy is released by the system to the surrounding but no work is done.

Calculate the internal energy change in each of the following systems. System II: No heat with surrounding but 25 KJ of work is done on the system.

Express the change in internal energy of a system when (i) No heat is absorbed by the system from the surroundings, but work (w) is done on the system. What type of wall does the system have?

Calculate the change in internal energy of a system which absorbs 100 J of heat and does 215 J of work.

Calculate the change in the internal energy of a system which absorbs '500 J' of heat, and does work equivalent to '200 J' on the surroundigs.

Express the change in internal energy of a system when (ii) No work is done on the system, but q amount of heat is taken out from the system and given to the surroundings. What type of wall does the system have?

Internal energy U of a system may change when