What is the formula for First Law of Thermodynamics Calculator (ΔU=Q−W)?

Core formula: ΔU = Q − W. The tool returns results instantly using this formula and the selected parameters.

First Law of Thermodynamics Calculator (ΔU=Q−W)

Solve internal energy change, heat absorbed or work done via the first law ΔU = Q − W (energy conservation).

Key points

First Law of Thermodynamics Calculator (ΔU=Q−W): Solve internal energy change, heat absorbed or work done via the first law ΔU = Q − W (energy conservation). Formula: ΔU = Q − W. Enter parameters on the DD-CAT IDE online tool page to get results instantly, with a calculation-model diagram that updates with the inputs. First law of thermodynamics (energy conservation): internal energy change ΔU = heat absorbed Q − work done W. Sign convention: heat absorbed by the system Q is positive and work done by the system W is positive; textbooks may differ, so stay consistent.

Inputs

ΔU = Q − W

Calculation model (updates with parameters)

Internal energy change ΔU	600 JJ	ΔU = Q − W
Heat absorbed Q	1 kJJ
Work done W	400 JJ
Energy conservation check	0J	Q − W − ΔU should equal 0

Engineering notes

First law of thermodynamics (energy conservation): internal energy change ΔU = heat absorbed Q − work done W.
Sign convention: heat absorbed by the system Q is positive and work done by the system W is positive; textbooks may differ, so stay consistent.
For an isochoric process W=0, so ΔU=Q; for an isothermal ideal gas ΔU=0, so Q=W.

FAQ

What is First Law of Thermodynamics Calculator (ΔU=Q−W) for?: Solve internal energy change, heat absorbed or work done via the first law ΔU = Q − W (energy conservation).
What is the formula for First Law of Thermodynamics Calculator (ΔU=Q−W)?: Core formula: ΔU = Q − W. The tool returns results instantly using this formula and the selected parameters.
What engineering notes should I keep in mind when using First Law of Thermodynamics Calculator (ΔU=Q−W)?: First law of thermodynamics (energy conservation): internal energy change ΔU = heat absorbed Q − work done W. Sign convention: heat absorbed by the system Q is positive and work done by the system W is positive; textbooks may differ, so stay consistent. For an isochoric process W=0, so ΔU=Q; for an isothermal ideal gas ΔU=0, so Q=W.