Question

In a process 500 calories of heat is given to a system and at the same time 100 joules of work is done on the system The increase in internal energy of the system is ?

Answer 1

In a process 500 calories of heat is given to a system and at the same time 100 joules of work is done on the system. The increase in internal energy of the system is 2200 joules.

1) In physics, the general notation is, heat supplied to a system is taken as positive and vise versa.

2) Again, work done on the system is taken as negetive and vise versa.

3) By first law of thermodynamics,

Q = U + W.

4) Given data, Q = 500 cal = 500 * 4.2 joules = 2100 joules.

5) W = ( -100 joules )

6) So, change in internal energy (U) = 2100 - (-100) joules = 2200 joules