Acceleration of F1 car

[Scotracer]

alelanza,

I know very little about dragsters, but here’s what came to mind. I would say they use parachutes....

The NHRA requires parachutes over a certain speed. The most important reason they are used is because they provide directional stability while slowing the car. With the lack of suspension, very long wheelbase, narrow track, and extreme rearward weight bias there's no way a top fuel dragster or funny car could safely stop from over 300mph by only braking the wheels, they would lose control. Some fighter jets and the space shuttle use drag chutes for the same reason.

But I do agree that they look totally cool. Plus they provide plenty of square footage for sponsorship advertisement.

Regards,
riff raff

I'd agree with the directional stability reason - afterall, parachutes aren't the most efficient way of actually decelerating the vehicle.

[Edis]

but I have always wondered why drag cars have to use parachutes instead of regular brakes

I know very little about dragsters, but here’s what came to mind. I would say they use parachutes,

Because they can:....

Valid arguments, but I think our esteemed moderator is also wrestling with the concept of Power being Force times Speed.

- This concept applies to deccelleration as well, why the braking power at that speed would probably cook the hydraulics.
- Also, aerodynamic resistance goes with the square of the speed, why a parachute is four times as efficient at 500 km/h as at 250, while the breaking power disappears into thin air so to speak.

If it cooks the hydraulics there is a design flaw. Friction brakes are intended to heat the brake disc, not the hydraulic actuator.

Regarding the power required to brake a dragster, a 1 ton dragster at 500 km/h is still peanuts compared to say a 180 ton Concorde during an aborted take off.

[alelanza]

Been watching top fuel for a couple weeks now, and i feel i must restate what i wrote before. I think there's one huge reason why parachutes are used, and no one mentioned it before.
Once these cars get to the 400 m mark, there's no telling what's left of the car. There's a big chance the tyres are destroyed, either due to simply being ripped against the tarmac, or destroyed by a piece of exploding engine head (yes it happens) or what have you. The supercharger belt may have snapped and wrapped itself around an axle. Your engine may be on fire or simply dead so brake assistance may not be there for you.
However an external parachute, which for the most part are relatively safely placed in the back, is your best bet at having a braking chance. I'd say this is THE reason why you want chutes....