Effect of Weight on Top Speed?

I have been arguing for some while with my kin about whether weight adversely impacts top speed.

I believe that my kin is mistaken about the difference between "torque" and "horsepower" with respect to maximum velocity of a vehicle. While we can agree that drag, tire width, RPM, gear ratios and else combine with horsepower to affect top speed, we are at odds about whether weight is a major component to top speed, and neither of us can appreciate torque and HP in the same fashion.

My belief has been that "power" itself is the rate at which newtonian/electric ("joule") energy can be exerted. Whereas, I've always looked upon torque as a function of "work", force exerted over a given distance. I've long postulated that it is because of these facets of physics that sprinters (having the extraordinarily strong legs as they do and the very low overall weight as they carry) are able to accelerate as quickly as they can, and certain free runners are capable of reaching the absolute maximum velocity that they can. Also because of these rules - at the same time - is why some great sprinters who excel at blasting off of the line can't run quite as fast as other runners, who may not be nearly as strong (and therefore not nearly able to produce as much *torque* from the line).

I've seen some untrained athletes - gifted ones, perhaps - outrun (top speed wise) prime sprinters who have been training for years, albeit not nearly with the same rate of acceleration. Those untrained yet very fast athletes performed higher on kinesthetic intelligence tests, indicating an moreefficientt (and therefore faster) neural networking that allows for more coordination in muscle exertions and greater maximum, maintainable "functioning" speed as a result (literally translating to a faster physical motion). However, lacking the muscle strength (the "torque") that they did, the untrained runners were unable to produce the same level of acceleration as the practiced sprinters, which I attribute to a lower torque-to-weight ratio (at a low-end power rate). The actual running trials demonstrated precisely the kinesthetic effect foreshadowed by the mathematical calculations prior to the race.

I've seen the same things apply to cars as well.

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  • 7 years ago
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    Weight does affect top speed. For vehicles on level ground, more weight slightly increases rolling friction, especially in tires, thus, slightly decreasing top speed.

    For athletes, weight makes big difference for a given set of legs, as the muscles spend more effort holding up the heavy guy, thus, less is available to help move him. The acceleration of the heavy guy is hurt more than his top speed though, because it takes more work to speed him up, in addition to more effort to hold him up.

    You can't really generalize this to different atheletes very well though. There are so many variables: muscle/bone/joint geometry, fast/slow twitch tissue, skill levels, etc.

    Source(s): Mech E degree and personal experience, especially on the heavy guy thing!
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  • 3 years ago

    Newtons guidelines of physics. An merchandise at relax has a tendency to stay at relax without outside forces appearing on it. An merchandise in action has a tendency to stay in action without outside forces appearing on it. the suitable speed of a vehicle is only depending on the flexibility to weight ratio and the drag, both fluid and frictional. So the tires' friction with the line and the drag on the air impression the suitable speed, besides as with the flexibility to have the flexibility to flow a particular mass at that speed. faster or later the motorized vehicle will not accelerate because the stress of the air and floor urgent on the body of the motorized vehicle equals the quantity of ahead thrust you'll get from the engine.

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