Question

A system suffers an increase in internal energy of 80 J and at the same time has 50 J of work done on it. What is the heat change of the system?

Answer 1

Answer :

Increase in internal energy = 80J

Work done on system = +50J

We have to find the heat change of the system$.$

Internal energy (U) is the total energy within a system. It is the sun of all types of energies (chemical, electrical, mechanical or any other type) of the system and is a state function.

The first law of thermodynamics :

• ∆U = q + W ..... (I)

★ For adiabatic change,

• ∆U = U₂ - U₁ = Wad

where, Wad is work done when no heat is exchanged i.e; q = 0

★ ∆U = q(v) when no work is done at constant volume.

By substituting the given values in equation (I), we get

➝ ∆U = q + W

➝ 80 = q + 50

➝ q = 80 - 50

➝ q = 30 J

Answer 2

Answer:

delta U=q+w

given:-deltau=80J

w=50J

80=q+50

q=30J