Very Confused About This, Please Help

My confusion has something to do with slipstreaming.

Me and my friend were arguing about weight on MSN when he went on Wikipedia (http://en.wikipedia.org/wiki/Slipstream) and quoted this:

"In addition, the leading object will be able to move faster than it could independently because the rear object reduces the effect of the low-pressure region on the leading object."

This got me really confused, how does the rear object affect the object in front?

Isn't it the other way around, the front shouldn't be affected at all?

Please help explain this, or is it a mistake on Wikipedia because at the top it says:

"This article needs additional citations for verification."

Please help explain this to me.

Thank you.

KA would be best to explain this, but my understanding is because you share the wind resistance between the two or more cars, best example to use is look at NASCAR's on a Super speedway such as Daytona or Talledega, and watch how they line up in say groups of 6-8 cars and they will go faster than the others around the lap by a good 5-10mph faster.

I can't explain the exact details of this though, KA best one for that :P

But why would the car in front be affected???

It's not receiving any slipstream. This is why I am very confused.

Airflow is still something of a black art, the car behind definitely gains an advantage once it is truly in the slipstream of the car ahead. The car in front may still gain an advantage too as mentioned in the wiki article, I can't comment definately on it having never truly studied aerodynamics at any kind of academic level, however what I can make some sense of is the mention of the change in the low pressure area behind the car in front.

If the car behind gets close enough to the car in front the affect of the car being so close behind may help to lessen the drag from the car in front due to the pressure change caused by the car behind being where it is. Even though the air is downstream of the car it is still "attatched" to a certain degree and changes in pressure to the area behind the car where the airflow is still semi-attatched can alter the characteristics of the lead car. 

The phenomenon can be seen when cars run in high humidity and high temperature environments like in Malaysia before the afternoon storms in these conditions you can observe the air vortices shedding from the rear wing end plates. I cannot find the picture now but there was an onboard shot of the McLaren running in the damp at Belgium where, due to the rain, it was possible to observe a large vortex running off the medial trailing edge of the front wing, directed along the splitter and udner the car.

If the car behind gets close enough to the car in front the affect of the car being so close behind may help to lessen the drag from the car in front due to the pressure change caused by the car behind being where it is. Even though the air is downstream of the car it is still "attatched" to a certain degree and changes in pressure to the area behind the car where the airflow is still semi-attatched can alter the characteristics of the lead car.

KimisApprentice

But aren't they driving into the wind?

As in the wind goes over the car?

This should mean that anything behind it shouldn't affect it, only the things in front of it.
Please help lessen my confusion KA.

Ummm, XSamFisherX, are you talking about the car behind nudging the car in front?
If so, I'm afraid that's not what I'm talking about.

I'm just talking about genera slipstreaming, how will the car in front go faster because there is a car behind?

Sorry if you just combusted :P

Ok, how about we try this a different way.

Imagine a boat travelling through the water, when it goes fast enough it will create a bow wave which will push any objects that get in the way.

Now then for the your question the car at the back acts like the boat and the air in front of it is like the water. This means as it gets close to the car in front the bow wave of air will push on the front car making it go faster.

No, it is the exact same thing. The only thing that varies is the amount of air between the cars. I can nudge someone with a pillow, lead brick, air or nothing between me and the nudgee. XSamFisherX

nudgee? If that's not a real word, you need to contact someone who makes a dictionary and tell them to put it in there! That's awesome!

WOW?

Seriously? You can "push" the air to nudge the car in front of you?

Is this the answer to by question?

WOW?

Seriously? You can "push" the air to nudge the car in front of you?

Is this the answer to by question?

Air has mass, so it's just as SamFisher speculates, it's entriely possible that this is what's happening in that situation; the car behind could use air to push the car in front.

Or the car in front is making the air off the back of the lead car detatch quicker reducing it's drag.

Air has mass

KimisApprentice

Cars can pick up the tow say a good 50m away from the cars I'm guessing KA? But for the pushing of the air against another car you'd have to be a a car length behind to get the full effect of the tow this creates the low pressure and in effect as explained pushing the pressurized mass of air against the car ahead giving an extra 3-5kmh to the car in front, This shows in Indy cars and NASCAR especially since they race round ovals and do this lap after lap.

Least... this is my understand of Dabest's question :P

I meant how far behind do you have to be "nudge" the car ahead.dabest2500

[QUOTE="dabest2500"]I meant how far behind do you have to be "nudge" the car ahead.XSamFisherX

Oh right stupid me, thanks for everyone who helped!

I must admit I wasn't aware of this phenomenon either. You learn something new every day I guess.

Knowledge +1

I must admit I wasn't aware of this phenomenon either. You learn something new every day I guess.

Knowledge +1

cjek

Yep, I learnt a hell of a lot just now.