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Science-Related Homework Help Physics Topic started by: smj545 on Dec 6, 2012



Title: Why is a bouncing ball not an example of simple harmonic motion?
Post by: smj545 on Dec 6, 2012
Why is a bouncing ball not an example of simple harmonic motion?

Thanks


Title: Why is a bouncing ball not an example of simple harmonic motion?
Post by: micro205 on Dec 6, 2012
It would be periodic motion.  It doesn't follow a sinusoidal curve, because the bounce gets less and less each time.  If you imagine a bouncing ball, it's maximum velocity is right before and right after it hits the ground.  In simple harmonic motion, the maximum velocity occurs in the middle of the amplitude.


Title: Why is a bouncing ball not an example of simple harmonic motion?
Post by: dattrussianki on Dec 6, 2012
Because the ball doesn't bounce symmetrically...dunno how to explain it.   Harmonic motion is when something goes back and forth, like a spring or something spinning, about a central axis.  Balls don't do that


Title: Why is a bouncing ball not an example of simple harmonic motion?
Post by: Fireburns92 on Dec 6, 2012
Because the acting force is not of the form F = -kx.
In the motion of a bouncing ball, during most of the time the force is F = mg, and the motion is either uniformly accelerated or uniformly retarded.


Title: Why is a bouncing ball not an example of simple harmonic motion?
Post by: smkt025 on Dec 6, 2012
Because it's not simple.  Even if you make the necessary simplifying assumptions that the bounce is lossless, motion is purely vertical, and there's no spin, the bounce force is not linear with distance.  It's very small at first contact, but much stronger than linear at maximum distortion.  It is always influenced by gravity, but influenced by the spring-like force only when it's in contact with the ground.