Question

A system is provided 50 J of heat and work done on the system is 10 J. What is change in internal energy ?

• A. \(40\) J
• B. \(60\) J
• C. \(30\) J
• D. \(50\) J

Hint:

Use the first law \(\Delta U = q + w\) with both terms positive here.

Answer 1

The Correct Option is B

Step 1: Track energy in
The system gains 50 J as heat and 10 J as work. Both are energy entering the system.

Step 2: Add them
Total energy stored: $50 + 10 = 60$ J, so $\Delta U = +60$ J, option (B).

Final Answer:
The change in internal energy is 60 J, option (B). \[ \boxed{60\ \text{J}} \]