If the amount of heat given to a system is 50 J and work done on the system is 15 J, then change in internal energy of the system will be

Options

A. 35 J
B. 50 J
C. 65 J
D. 15 J

Explanation

To find the change in internal energy of the system, we can use the first law of thermodynamics, which is given by the equation:

\[ \Delta U = Q - W \]

where:
- \(\Delta U\) is the change in internal energy,
- \(Q\) is the heat added to the system,
- \(W\) is the work done by the system.

In this case:
- The amount of heat given to the system, \(Q = 50 \, \text{J}\).
- The work done on the system, \(W = 15 \, \text{J}\). However, since work done on the system is considered negative in the context of the first law of thermodynamics, we will use \(W = -15 \, \text{J}\).

Now, substituting the values into the equation:

\[ \Delta U = Q - W \]
\[ \Delta U = 50 \, \text{J} - (-15 \, \text{J}) \]
\[ \Delta U = 50 \, \text{J} + 15 \, \text{J} \]
\[ \Delta U = 65 \, \text{J} \]

Thus, the change in internal energy of the system is \(65 \, \text{J}\).