1. What is the Change In Internal Energy Formula?

The Change In Internal Energy formula calculates the change in internal energy of a system using mass, specific heat capacity at constant volume, and temperature change. It is a fundamental equation in thermodynamics.

2. How Does the Calculator Work?

The calculator uses the Change In Internal Energy formula:

Where:

• \( \Delta U \) — Change in internal energy (J)
• \( m \) — Mass of the substance (kg)
• \( C_v \) — Specific heat capacity at constant volume (J/kg K)
• \( \Delta T \) — Temperature change (K)

Explanation: The formula calculates the energy change in a system when its temperature changes at constant volume, accounting for the material's heat capacity and mass.

3. Importance of Internal Energy Calculation

Details: Calculating change in internal energy is essential for understanding energy transfers in thermodynamic systems, analyzing heat engines, and studying phase changes in materials.

4. Using the Calculator

Tips: Enter mass in kilograms, specific heat capacity in J/kg K, and temperature change in Kelvin. All values must be valid (mass > 0, Cv > 0).

5. Frequently Asked Questions (FAQ)

Q1: What is internal energy?
A: Internal energy is the total energy contained within a system, including kinetic and potential energy at the molecular level.

Q2: When is this formula applicable?
A: This formula applies to systems undergoing temperature changes at constant volume, particularly for ideal gases and incompressible substances.

Q3: What's the difference between Cv and Cp?
A: Cv is specific heat at constant volume, while Cp is at constant pressure. For ideal gases, Cp = Cv + R, where R is the gas constant.

Q4: Can this be used for phase changes?
A: No, this formula is for temperature changes only. Phase changes require latent heat calculations (Q = m × L).

Q5: What are typical Cv values?
A: Cv varies by material: water ≈ 4186 J/kg K, air ≈ 718 J/kg K, aluminum ≈ 900 J/kg K, etc.