1. What is Specific Internal Energy?

Specific internal energy (u) is the internal energy per unit mass of a substance, representing the energy associated with molecular motion and intermolecular forces in water.

2. How Does the Calculator Work?

The calculator uses the simplified equation:

Where:

• \( u \) — Specific internal energy (J/kg)
• \( c \) — Specific heat capacity of water (J/kg°C)
• \( \Delta T \) — Temperature difference (°C)

Explanation: This calculates the energy change per unit mass when water temperature changes, assuming constant specific heat capacity.

3. Importance of Internal Energy Calculation

Details: Calculating internal energy is essential for thermodynamic analysis, heat transfer calculations, and designing thermal systems involving water.

4. Using the Calculator

Tips: Enter specific heat capacity of water (typically ~4186 J/kg°C for liquid water) and temperature difference. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What's the typical specific heat of water?
A: For liquid water at 20°C, it's approximately 4186 J/kg°C. For ice (~2100 J/kg°C) and steam (~2010 J/kg°C) it differs.

Q2: Does this account for phase changes?
A: No, this simplified version only calculates sensible heat changes, not latent heat during phase transitions.

Q3: Why is internal energy important?
A: It's fundamental in thermodynamics for analyzing energy transfers in heating/cooling systems, power plants, and chemical processes.

Q4: How accurate is this calculation?
A: Reasonable for small temperature ranges where specific heat is nearly constant. For large ranges, integration of temperature-dependent c(T) is needed.

Q5: Can this be used for other substances?
A: The same principle applies, but you must use the correct specific heat value for the substance in question.