Statement I: When a rotating disc is placed on a coaxial disc at rest and they reach a common angular speed through friction, the total internal energy of the two discs does not change.
Statement II: Energy is conserved in the process.

Question

Statement I: When a rotating disc is placed on a coaxial disc at rest and they reach a common angular speed through friction, the total internal energy of the two discs does not change.

Statement II: Energy is conserved in the process.

TestHub · Accepted Answer

Friction turns part of the rotational kinetic energy into heat. Total energy is conserved (Statement II is true), but the internal energy of the discs rises, so Statement I is false. C.

Physics - Heat & Thermo Question with Solution | TestHub

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