Regulation Question--5.2.2

[Mac Man]

Greetings y'all from the Rocky Mountains,

Some friends and I have been studying the tech. regs., and are a bit baffled by rule 5.2.2 which states:

5.2.2) The total amount of recoverable energy stored on the car must not exceed 300kJ, any of which may be recovered at a rate greater than 2kW must not exceed 20kJ.

':shock:'

So, what does this mean? Please help me out with this. Here in the land of Foot-Pounds and Horsepower, we don't quite grok the kJ and kW. I know that it is kilo-joules and kilo-watts, but how does it translate?

I've turned here, because I read most of the pages out there, and y'all seem to have the biggest clue about the technical side of the sport.

Derek

[Monstrobolaxa]

Hi Rockey Moutain neighbour....I live in Portugal...but lived (and go every summer) in Edmonton (Alberta, Canada).....the Rockies.....well....a little publicity....everypne before dieing visit the Rockey Moutains....thes mst beautifull place in the world....

Well back to the topic....

- 1 W (watt) = 1,341x 10^-3 Horsepower - W is a Power unit

- 1 J (Joule) = 0,7376 ft-lbf - J is a energy unit.

Analysing the article...(5.2.2....) i can't get to an imediate answer.....but I'll look it up on Friday...I have an exam on thursday.....and my girlfriend is hear.....haven't been with her in a month.....so see you all later

[Becker4]

maybe prohibiting battery powered electric engines, which could theoretically be used to give extra passing power on a long straightaway, or to allow for lower fuel loads on a qualifying run, or to clamp down on brakes harder, or any number or other things? any other ideas?

[Gliderpilot]

Greetings from a new person on the board!

I believe the rule has something to do with spring loaded flywheels etc.

The term 'recoverable' most likely means that you convert kinetic energy from the moving car (braking for a corner) into potential energy and it is then recovered to accelerate the car out of the corner.

[Monstrobolaxa]

Glider pilot might just have found the answer.

[Guest]

Give her one for me Monstro!!

[Mac Man]

Ok, so . . .

I am no engineer, but i have a pretty good grasp of mathematics, I think, er, I thought.
Using Monstro's numbers I arrived at:

1W=1.341 E-3= 0.001341 hp (US decimal)
conversely:
1hp=745.712W

1J=good times! (J=spliff) Whoops! Wrong J . . .

1J=0.7367ft-lbs
conversely:
1ft-lb=1.3574J

So far so good. Next I begin to question my math:

300kJ=300000J=221010ft-lbs! Seems a bit much.
2kW=2000W=2.682hp Sensible number here.
20kJ=20000J=14734ft-lbs! Again somewhat of an astronomical number.

Putting these numbers into the rule, it begins to look more like a rocket than a car being discussed:

5.2.2) The total amount of recoverable energy stored on the car must not exceed 221010ft-lbs, any of which may be recovered at a rate greater than 2.682hp must not exceed 14734ft-lbs.

As I said, I'm beginning to doubt either mymathematical abilities or the reality enveloping the F1 world. The kinetic/potential energy conversion via flywheels makes sense, but it seems like it would be a hell of a flywheel to store nearly a quarter-million ft-lbs of energy. So, I'm still having a little trouble wrapping my head around this.

thanks y'all

D-Rock

[joseff]

You have your units for energy, torque, power, etc. mixed up! See Monstro's explanation again. He clearly states which is which.

See, this is why the rest of the world sticks to the metric unit

BTW the USA is officially a metric country since 1978.

[Guest]

Ok, so . . .

I am no engineer, but i have a pretty good grasp of mathematics, I think, er, I thought.
Using Monstro's numbers I arrived at:

1W=1.341 E-3= 0.001341 hp (US decimal)
conversely:
1hp=745.712W

1J=good times! (J=spliff) Whoops! Wrong J . . .

1J=0.7367ft-lbs
conversely:
1ft-lb=1.3574J

So far so good. Next I begin to question my math:

300kJ=300000J=221010ft-lbs! Seems a bit much.
2kW=2000W=2.682hp Sensible number here.
20kJ=20000J=14734ft-lbs! Again somewhat of an astronomical number.

Putting these numbers into the rule, it begins to look more like a rocket than a car being discussed:

5.2.2) The total amount of recoverable energy stored on the car must not exceed 221010ft-lbs, any of which may be recovered at a rate greater than 2.682hp must not exceed 14734ft-lbs.

As I said, I'm beginning to doubt either mymathematical abilities or the reality enveloping the F1 world. The kinetic/potential energy conversion via flywheels makes sense, but it seems like it would be a hell of a flywheel to store nearly a quarter-million ft-lbs of energy. So, I'm still having a little trouble wrapping my head around this.

thanks y'all

D-Rock

Isn't there a 1hp=550ft/lb-s somewhere in there?

[Guest]

While we are on the subject of units. What exactly do you guys consider a kilogram? unit of mass? unit of weight? same thing as a Newton?

It seems that kilogram is readily used interchangeably with Newton as a measure of weight (or force). "The car must weigh 600kg's...."
So I'm just curious if it is customary to do this in Europe.

Because, by definition, if a kg is a unit of mass then what does something weigh when it weighs 1kg?

[Monstrobolaxa]

Well nothing weighs 1 kg.....kg is a unit of mass....weigh is the force, that earth (or a planet or some lind of force that pulls you down) applies on you.

Usually you say you weighed something but that is incorrect, and represent it in kg....scales messure your weight and convert it into mass......for example if you used the same scale on another planet your weight would be diferent but your mass would be the same, and the scale would show you a diferent mass.....so it's all a question of applying physics....and looking carefully at the theories.......

Being a soon of physics teachers and a nephew of one.....I've been hearing this all my life what a dumb life

[Guest2]

Hej G's
New here. Quite impressed with the tech stuff discussed.
kilogram is a unit of mass which is quite different from weight.
I believe Weight is mg (i.e mass x gravity). In a way you could also
say this a force (newtons) since Force (F) = mg (or(ma).
Also I think 1 kw = 1 kj/s (i.e the rate of doing work). Please correct
me if wrong, have not done this for a while.

[Goose]

Guest2 your right on the 1 kW = 1 kj/s

[guest2]

While we are on the subject of units. What exactly do you guys consider a kilogram? unit of mass? unit of weight? same thing as a Newton?

It seems that kilogram is readily used interchangeably with Newton as a measure of weight (or force). "The car must weigh 600kg's...."
So I'm just curious if it is customary to do this in Europe.

Because, by definition, if a kg is a unit of mass then what does something weigh when it weighs 1kg?

In every day terminology, if something weighs 1kg, what is infact meant is 1 kg/s (or N). Weights, measure, scales etc. in kg for most uses, are therefore calibrated to measure mg rather than just m. In engineering terms, 1kg is just that, 1kg and an engineer would be more interested in mass or force, or the force exerted by a mass on something or other etc etc etc.

[Monstrobolaxa]

Exactly....