Thursday, July 24, 2008

There's a Lot More to Going Fast Than the Horsepower Number

I think every physics student would know that. Still, this article on this particular vehicle called the "Atom" tries to illustrate why the vehicle's mass, and not just the "horsepower", certainly dictates how fast a vehicle can go and how quickly it can reach very high speeds.

The details of the physics lesson is that 200 horsepower doesn't sound like much, but when the car weighs less than 500 kilograms? Step up to the supercharged model like the one you see here and you get 300 horsepower, enough to launch the Atom to 100 km-h in three seconds.

But still, did anyone else caught the unintended pun early in the article? I'm guessing that even the writer didn't notice it.

That seems odd as you sit so low in the Atom, and you're so exposed to the elements with wind rushing up your legs through the sides of the car that it feels as though you're travelling twice as fast as you actually are.

Do you see it? Atom.... exposed to the elements.... Oh, never mind!




Matt said...

I don't care about the physics, I just know I want one:

Doctor Pion said...

Sweet, although I knew it was power to weight when I was but a wee sprout in Indiana and soon learned that power to drag is the only thing that matters for speed.

That does look like a fun car, but I'd never drive it on the street in the US. This one, the BBR Shark has about the same power to weight ratio (owner is closed mouth about power but says it exceeds 250 hp on 750 pounds plus driver) with the added feature of a well designed wing. It drag limits at 80 mph, but it can drive on the ceiling at that speed due to the downforce it generates. Only 2 g in a corner so not F1 territory, but interesting to watch from the driver's seat. When you hear the rpm max out, he is close to 80 mph but probably slower since this is all uphill.

Info above is first hand from the owner; I've seen it run in SCCA competition.