A particle performs simple harmonic motion with frequency f. What is the frequency with which its kinetic energy oscillates?

Correct answer: 2f

Solution

KE = (1/2)mA²*omega²*cos²(omega*t) = (1/4)mA²*omega²*(1 + cos(2*omega*t)). The KE oscillates with angular frequency 2*omega, hence frequency 2f.

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