Question

6) If a system has 48 J of work done on it and absorbs 22 J of heat, what is the value of ΔE for this change?

Answer 1

ANSWER

ΔE = 70 J

EXPLANATION

Given:

• The work done on the system, W = 48 J

,

• The heat absorbed by the system, Q = 22 J

Find:

• The change of energy of the system, ΔE

We will use the convention where:

• Heat transferred to the system: positive (otherwise negative)

,

• Work done on the system: positive (otherwise negative)

By the first law of thermodynamics,

$\Delta E=Q+W$

Replace with the known values and solve,

$\Delta E=22J+48J=70J$

Hence, the change in the system's internal energy is 70 J.