Question

A system uses 2,380 J of energy to do work as 12,900 J of heat are added to the system. What is the change in internal energy of the system?

Answer 1

The internal energy of the system is characterized by the equation U = Q + W where U is the internal energy, Q is the heat and W is work. You are given 2,380 J of energy to do work as 12,900 J of heat so add up. The internal energy is 15,280J.

Answer 2

Explanation:

The relation between change in internal energy, work and heat is as follows.

                    $Q = \Delta U + W$

where,       Q = heat absorbed or released by the system

                $\Delta U$ = change in internal energy

                W = work done by or on the system

It is given that system uses 2,380 J of energy to do work. This means that work is done by the system therefore, the value of work done by the system is negative. Heat added to the system is 12,900 J.

Therefore, calculate change in internal energy as follows.

                       $\Delta U = Q - W$

                               = 12,900 J - (-2,380 J)

                               = (12,900 + 2,380) J

                               = 15,280 J

Thus, we can conclude that the change in internal energy of the system is 15,280 J.