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Energy against time runs at 2f

● VERBATIM — examined word-for-word

KE and PE each oscillate at frequency 2f — the particle hits max speed twice per cycle. The energy graphs are NOT at f.

What this actually means

The mass passes through maximum speed twice per cycle, once in each direction, so kinetic energy peaks twice per cycle. The energy graphs therefore oscillate at 2f.

Sketch marks hang on two facts: energy curves are never negative, and they run at double the displacement frequency.

The trap

Drawing energy–time graphs at f instead of 2f.

Prove it — watch it be true

  1. Switch the energy plot to the vs-time view and run one full oscillation
  2. Count peaks against the displacement cycle: KE peaks twice per cycle, and so does PE — the energy curves run at 2f
  3. Note both curves stay above zero the whole way: energy graphs are never negative, unlike x, v and a
Open shm-energy lab →
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