F1 In Schools help : Pudin's project

[pudin]

About your car: not sure if it complies with rule 3g: all the wheel must be visable from above.
Hope this helps.

Actually,the car's wheels does wholly visible from the top and bottom.
There are 2 small gaps between the tyre which length jsut about 1mm.

[pudin]

Hey,we've made a run today,just after the rain so the air humidity quite high,we did at an astonishing 1.03 sec.Just 0.01 behind the official world record.Hope this time stayed at the national champs.
Thanks for everyone who contribute building this car.
Greetings from Malaysia!

[hollus]

Why would humidity in the air be a bad thing?
Sorry, I just re-read your post, you never said it was bad.

[pudin]

What i meant was what the humidity of air is higher thus slowering the car even more.Basizeland do talk about this in my post and his post.Recheck the posts.The condition of air is really affect the car.Whether slowing the car down or accelerating the car even faster,it depends.

Thanks everyone our car ran a time of 1.049sec but it was really humid which slows the cars down because the air is thicker.

We had a promo run with the current Australian record holder which set a time of 0.985sec and we beat that car so our car would have been really fast if it wasn't as humid.

[flynfrog]

lets see some pics

[hollus]

Thanks Pudin.
I had that post in my head when I read your time (congratulations, BTW, very promising). It is only because there was a similar discussion in the Interlagos thread that I noticed it this time.
I agree that thicker air would slow the car down, but I am not so sure that humidity makes the air thicker. It certainly makes it feel thicker to us humans, but I would think that the approx 1% of H2O air can hold (figure taken from teh back of my head an likely inexact) would displace an equivalent 1% of mostly O2 and N2, and H2O is a lighter molecule than those, thus reducing air density.
I am more than happy to be corrected, though!

[Rugby GP]

The air will become denser because it is being filled with water-H20 which is denser than air.

So when it is not humid, there are less H20 molecules in the air, so the air that the car displaces is on average lighter, so less energy is required.
Hope this helps.




By the way, I have made a separate post about how to create a VENTURI NOZZLE for the car.

If anyone can help me at all with this projec, please do. Pudin: you may want to use the nozzle for your car aswell.

[pudin]

The air will become denser because it is being filled with water-H20 which is denser than air.

So when it is not humid, there are less H20 molecules in the air, so the air that the car displaces is on average lighter, so less energy is required.
Hope this helps.




By the way, I have made a separate post about how to create a VENTURI NOZZLE for the car.

If anyone can help me at all with this projec, please do. Pudin: you may want to use the nozzle for your car aswell.

That is pretty much what i meant before.
And about the nozzle,i think our rules stated that there are no other implants should be at the nozzle,but maybe i'll give it a try to my car.
Maybe it could break the 1 sec barrier with the implants planted at my car.

[hollus]

From the wiki (density of air page):

Water vapor

The addition of water vapor to air (making the air humid) reduces the density of the air, which may at first appear contrary to logic.

This occurs because the molecular mass of water (18 g/mol) is less than the molecular mass of dry air (around 29 g/mol). For any gas, at a given temperature and pressure, the number of molecules present is constant for a particular volume (see Avogadro's Law). So when water molecules (vapor) are added to a given volume of air, the dry air molecules must decrease by the same number, to keep the pressure or temperature from increasing. Hence the mass per unit volume of the gas (its density) decreases.

[Rugby GP]

The 18g/mol is refering to the mass of one MOLECULE of water. It does not take into account how tightly packed they are. Although a water molecule may be lighter than an average air molecule, the air molecules are in gas state, and so they have a lower density than the water.

Therefore what you said about "the dry air molecules must decrease by the same number" is false because if you say add 1cm^3 of water, you are getting rid of 1cm^3 of water. And which has a larger density, water or air?

I am assuming that water vapour is tiny droplets of water like steam from the kettle. If water vapour is individual molecules of water with no hydrogen bonds between them, you are right. I think this might be where everyone is going wrong

[hollus]

Steam (as in water boiled at over 100C) is individual water molecules. You could call Steam "pure water vapor".
In moist air, you have about 1% water, and 99% the usual gases in air, all of them as free molecules, with few to none hydrogen bonds. It is basically a bit of steam diluted in air.

[Izzy410]

Sorry, i have been busy and i just reread that i promised to teach you how to insert high velocity air into the windtunnel. I COMPLETELY FORGOT SO I AM VERY VERY SORRY!

Okay, competition in a few day, guys, which school are you from?

Adroit is taking on SMK Agama Johor Bharu something like that. i hope that aint you guys

See you there, btw what's your car final mass?

[pudin]

Sorry, i have been busy and i just reread that i promised to teach you how to insert high velocity air into the windtunnel. I COMPLETELY FORGOT SO I AM VERY VERY SORRY!

Okay, competition in a few day, guys, which school are you from?

Adroit is taking on SMK Agama Johor Bharu something like that. i hope that aint you guys

See you there, btw what's your car final mass?

We're not SMKA Johor Bahru,its okay about the windtunnel,i also forgot that u promised to me.
lol
All the best!
Our car's mass is at 55g
=D

lets see some pics

If i have some time ill upload some of the car's picture,

[pudin]

We've run another test in the evening around 5 p.m and our time was 0.995.
That time we achieve when we remove the attachable rear aerofoil and front aerofoil all together.
That was under a second dudes.
I just can't believe my eyes.