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Physics/How can someone run faster.


Hey Steve. I'm a junior in high school, and working on my science fair project. I've chosen to answer the question, "What factors make someone run faster". I know that height and weight have major contributions, but my main interest is why is it that 2 people with almost the same height and build can have totally different speeds of running. I've done some research on the internet but haven't found many results. So I'm just wondering if you know anything about this topic or any websites that talk about it.

I'm a physicist, not a kinesiologist.  The difference is largely going to be medical, since the straight-up physics says that two people with the same build would have the same pendulum motion rhythms and stride.  Things like flexibility will seriously affect stride length, of course.  Muscles and the support of the circulatory system are the big factors.  For longer races, the circulatory system and the body's ability to take in oxygen and expel CO2 and waste heat are the physics factors, but those are largely determined by medical factors and training.

In short, you asked the right type of who can tell you that the basic physics says that you're right to be confused and to point you towards the source of the difference.  You need to focus on what makes their muscles, energy production, and flexibility different because the kinetics of the running are essentially identical for basically identical runners.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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