Discussion
Remember that the kinetic energy of a moving mass (such as a fuel car) goes up in value to the square of the speed. In other words, taking 316 and 326 mph as our examples, the relative force needed to stop our car from 316 is: (316/326)squared
Or 0.94 of the force needed from 326.
If we assume an average shutdown area of 1000 yards, or 3000 feet, the extra distance involved works out to 3320/3000
or 1.106 times the distance.
Put those two together, and the 1000ft 316 pass gains an added 'safety margin' of 17% over a 1320ft 326 on a track with 1000yds available beyond the quarter mile.
Or 0.94 of the force needed from 326.
If we assume an average shutdown area of 1000 yards, or 3000 feet, the extra distance involved works out to 3320/3000
or 1.106 times the distance.
Put those two together, and the 1000ft 316 pass gains an added 'safety margin' of 17% over a 1320ft 326 on a track with 1000yds available beyond the quarter mile.
1000 foot is obviously the nhra responding to a situation while an answer is found.The answer will lay in the build of the car ,it may be much better chutes thet are more fire retardent,even if they cost more,say 5000 dollars it would be good insurance as apposed to current 400 dollar nylon jobies,or perhaps a wing deck that stays with the chassis, these could all be regulated and would help chute deployment.A car on bonneville with no brakes no chutes and an unconsiouse driver will take miles to stop not a few hundred feet.
Edited by fester426 on Sunday 27th July 18:03
Chris Isaacs said:
Remember that the kinetic energy of a moving mass (such as a fuel car) goes up in value to the square of the speed. In other words, taking 316 and 326 mph as our examples, the relative force needed to stop our car from 316 is: (316/326)squared
Or 0.94 of the force needed from 326.
If we assume an average shutdown area of 1000 yards, or 3000 feet, the extra distance involved works out to 3320/3000
or 1.106 times the distance.
Put those two together, and the 1000ft 316 pass gains an added 'safety margin' of 17% over a 1320ft 326 on a track with 1000yds available beyond the quarter mile.
ah, but....SPR rises over the 1/4 mile, many USA strips fall, so we dont need as much runoff/shutdown area....Or 0.94 of the force needed from 326.
If we assume an average shutdown area of 1000 yards, or 3000 feet, the extra distance involved works out to 3320/3000
or 1.106 times the distance.
Put those two together, and the 1000ft 316 pass gains an added 'safety margin' of 17% over a 1320ft 326 on a track with 1000yds available beyond the quarter mile.
Dont forget that old chestnut,that a car on fire no brakes no parachutes doing 300 mph wether its slightly uphill or slightly down hill will take miles and miles to stop ,ask people on the saltflats,also take into consideration that the majority of salt lake racers strive to get in the 200mph club not the 300 mph club.
veryoldfart said:
ah, but....SPR rises over the 1/4 mile, many USA strips fall, so we dont need as much runoff/shutdown area....
ah, but....SPR's shutdown area then runs back downhil again after the finish line, so we do.As Chris has suggested, speed isnt so much the issue as much as momentum and kinetic energy, both of which are a product of mass as well as velocity. Vanishing Point and Oxygen never, as I recall, had much difficulty with the shutdown area at SPR. The majority of cars in recent years that have had trouble stopping in time seem to be Pro Mods...
Jon C said:
veryoldfart said:
ah, but....SPR rises over the 1/4 mile, many USA strips fall, so we dont need as much runoff/shutdown area....
ah, but....SPR's shutdown area then runs back downhil again after the finish line, so we do.As Chris has suggested, speed isnt so much the issue as much as momentum and kinetic energy, both of which are a product of mass as well as velocity. Vanishing Point and Oxygen never, as I recall, had much difficulty with the shutdown area at SPR. The majority of cars in recent years that have had trouble stopping in time seem to be Pro Mods...
1. The problem statement, all variables and given/known data
An ice-skater, with a mass of 60.0 kg, glides in a circle of radius 1.4 m with a tangential speed of 6.0 m/s. A second skater, with a mass of 50.0 kg, glides on the same circular path with a tangential speed of 5.0 m/s. At an instant of time, both skaters grab the ends of a lightweight, rigid set of rods, set at 90 degrees to each other, that can freely rotate about a pole, fixed in place on the ice. A) If each rod is 1.4 m long what is the tangential speed of the skaters after they grab the rods? B) What is the direction of the angular momentum of the before and after the skaters "collide" with the rods?
Momentum is the product between mass and velocity. Being a vector quantity, it has a direction, and the direction is very important when doing momentum calculations. Momentum is not a thing that we can see, but it does explain many things that go on in physics.
Momentum (kg m/s) = mass (kg) x velocity (m/s)
Edited by veryoldfart on Sunday 27th July 18:33
fester426 said:
Dont forget that old chestnut,that a car on fire no brakes no parachutes doing 300 mph wether its slightly uphill or slightly down hill will take miles and miles to stop ,ask people on the saltflats,also take into consideration that the majority of salt lake racers strive to get in the 200mph club not the 300 mph club.
hence the need for an automatic retarding system linked to a deadman sensor, at worst a vehicle passing the finish line should have no engine power available and an automatically applied main braking system. perhaps my question can be best answerd by Chris Izaccs being a builder of racecars or Bob Jarrat
Would it be possible, seen as the modern fuel cars have a fair amount of computer timers and actuators, to have a system that as the cars reach, say, 1000 feet some kind of sensor on the track sends a signal to the car which activates a device that automaticly deplys the chutes as i would imagine this is the point that a driver would be deplying the chutes on an average et pass also im sure an actuator could be used to brake the car once the chutes have deployed and there has been no input from the driver for what ever reason?
now im not saying this is a solution as if i have thought of it im sure some tech guy from a US race team has, i just wonderd if it would be workable.
but after all we can all pontificate and express our opinions and say that the answer is this or that but the current situation in the states can only and will only be resolved by the NHRA and the teams that belong to that organisation and what ever they do will eventually be implemented over here in Europe as Bob and the other fuel coupe guys know
Would it be possible, seen as the modern fuel cars have a fair amount of computer timers and actuators, to have a system that as the cars reach, say, 1000 feet some kind of sensor on the track sends a signal to the car which activates a device that automaticly deplys the chutes as i would imagine this is the point that a driver would be deplying the chutes on an average et pass also im sure an actuator could be used to brake the car once the chutes have deployed and there has been no input from the driver for what ever reason?
now im not saying this is a solution as if i have thought of it im sure some tech guy from a US race team has, i just wonderd if it would be workable.
but after all we can all pontificate and express our opinions and say that the answer is this or that but the current situation in the states can only and will only be resolved by the NHRA and the teams that belong to that organisation and what ever they do will eventually be implemented over here in Europe as Bob and the other fuel coupe guys know
yes,although i am not mr issacs or mr jarret, and obviously dont move in those heady hights,the word transponder comes to mind, single turn race cars ie short cicuit cars have transponders fitted to count the laps,this is an electrical device and from there it is only a short step to transponder activated ,solenoid deployed chute system which incidently at the moment burn off in a fire.However i dont think you are allowed electronic devices on fuel cars,perhaps they would make an exeption.However having an electronically deployed fireproof parachute.ie a chute that dosnt burn off when all the flame thingys get to it,could,just could give you an edge when it comes to stopping or at least slowing it to a survivable crash speed scenario,but hey what do i know....
ok, the transponder lives on the car,,,,when it travels over the acctuator buried in the ground, in this case the 990 foot mark it does it acctivating.On circuit cars its the finish line so therefore counts the laps hey we could make a lot of money here any body out there electrically minded.But what makes you think someone hasnt come up wiyh this allready.See there are ideas out there that could work
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