Work-Energy Theorem Concept Confusion

[Bleepbloopblop]

Hey, so I understand that Wapplied - W nonconservative = Energy final - Energy initial.

However, shouldn't the final energy be less than the initial energy because energy is lost in the form of heat?

If that's the case, the left side of the equation should be positive and the right side of the equation should be negative. Or did I write down the wrong equation??

Thanks for any help.

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[Lawpy]

Recall that the First Law of Thermodynamics states that the sum of the energy transfers is equal to the change in energy, or simply:

Energy final - Energy initial = heat transfer + work transfer -->
E = q + W;

The Work-Energy Theorem is a special case of the First Law, where there is no heat transfer. Saying that energy is lost in the form of heat means that you can't use the Work-Energy Theorem and are resorting to the First Law in its general form.

But even when sticking strictly with the Work-Energy Theorem as you presented:

Work applied - Work nonconservative = Energy final - Energy initial

Work applied is implying that work is done by the system, so it is negative work. Work done by nonconservative force is also negative, so both sides of the equation are negative as expected.

 

[Bleepbloopblop]

Recall that the First Law of Thermodynamics states that the sum of the energy transfers is equal to the change in energy, or simply:

Energy final - Energy initial = heat transfer + work transfer -->
E = q + W;

The Work-Energy Theorem is a special case of the First Law, where there is no heat transfer. Saying that energy is lost in the form of heat means that you can't use the Work-Energy Theorem and are resorting to the First Law in its general form.

But even when sticking strictly with the Work-Energy Theorem as you presented:

Work applied - Work nonconservative = Energy final - Energy initial

Work applied is implying that work is done by the system, so it is negative work. Work done by nonconservative force is also negative, so both sides of the equation are negative as expected.

Thank you very much for the help 🙂