# Simple Harmonic Motion

Discussion in 'MCAT Study Question Q&A' started by vapremed, May 27, 2008.

1. ### vapremed 2+ Year Member

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Examkrackers physics lecture book barely touches on harmonic motion... But it has some pretty tough and confusing questions in the 1001 book. Is this subject a favorite of the MCAT? I've taken 4 practice tests and haven't seen anything on it yet, asides from the basic concept of potential E to K.E. back to U.

Are there often full passages on this?

2. ### wooki 7+ Year Member

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i havent taken the mcats yet, but ive seen a SHM in several physics passages. off the topic of my head AAMC 3 has one. i am guessing if u know the basic eqn for SHM and pendulums [ie wavelength and period], you will be okay.

3. ### happygirl Member 5+ Year Member

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I can't really remember off the top of my head where shm has shown up, but I think it would be good to know. If it doesn't come up as a passage, they could be easy points for the stand alone questions.

4. ### koopa_troopa Junior Member 7+ Year Member

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You should know this topic well. It will either show up as a a straightforward question or a conceptual question. You should be able to make calculations as well as indicate at which point an object will have maximum/minimum velocity or acceleration.

5. ### Kaustikos Archerize It 10+ Year Member

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F = -kx
PE = 1/2kx^2

Those are honestly the ONLY two equations I have needed to "know" for harmonics thus far. Conceptually, familiarize yourself with where maximum velocity/energy occur and where maximum acceleration occurs as well. Know the difference between harmonic and non-harmonic motion.

Maximum PE = x maximum (maximum displacement) and max velocity occurs at x = 0 (right in transition). Acceleration occurs at the max at max displacement as well.

Also, one topic you might want to familiarize yourself with is Force and the idea of equal and opposing actions. There may be a question asking about a person holding a spring with two hands and compressing it with a constant force (say 20N) and the K = some number. Understand that although it may seem as though he is compressing it from both sides, it's not true and that the only change in x is 20N/k and not twice that (as some like myself originally thought).

Lastly, the occurance of harmonic motion has been small, but it has been there. You also want to familiarize yourself with Pendelums for sure because they may not ask about it in harmonics, they might ask about Tension or centripetal force.