# The physics of Webber’s Valencia crash

### Posted on 5th August 2010, 8:55Author Keith Collantine

Have a look at the current issue of Red Bulletin for an interesting perspective on Mark Webber’s terrifying crash with Heikki Kovalainen in Valencia.

Professor Thomas Schrefl does the maths on Webber’s aerial flip and comes up with some fascinating figures:

Doing the maths we see that the potential energy and the rotational energy take up about one to two per cent of the kinetic energy. After hitting the ground, Webber?óÔé¼Ôäós car slides towards the tyre barrier. Sliding means friction. The frictional force is FR = ?é?Ámg, whereby ?é?Á is the friction coefficient between the car and the ground. The work, FRs, done by the frictional force is calculated simply: force times distance to the barrier. Friction reduces the kinetic energy by roughly 10 per cent.

From the reduced kinetic energy we find the velocity at which Webber hits the barrier to be around 280kph (174mph, 4, 5).
Professor Thomas Schrefl

He reached a height of two metres during his brief flight seen in the video below:

Read more: Webber hits Kovalainen and flips

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## 83 comments on “The physics of Webber’s Valencia crash”

1. There’s a snippet in the new F1 Racing magazine that says Webber’s car was about 740 kilos, hit the barrier at about 80 mph, and reached a height of 5 meters.

2. First, there is no way it was going 174. I didn’t exactly rock Physics in college but a very light car going 200 is going to lose more than 30 mph after flipping through the air, first with the undertray forward, and then skidding on the ground for a couple seconds. He would have lost more than 30 mph in that total distance if he had just let off the gas, given the massive drag of an F1 car and drag at that high speed. I don’t buy it.

When you see how close Webber came to being nailed by his tire, as well as a fusilade of substantial debris raining in behind him as he hit the wall like a round of grape shot, you see how lucky he was.,

3. The tarmac/gravel run-off debate is lasting from many years. Basically FIA wants an all-tarmac everywhere. FIM doesn’t. FIA’s thinking is that in the most cases tarmac let cars not to roll (and recover from mistakes) and decrease braking space (supposing that all brakes, suspension, tyres and aero are functioning). So where FIA could they deploy all tarmac arrestor bed.

The problem occurs when there is a total loss of control. In any case where a mechanical failure occurs (remember the Gachnang’s Abu Dhabi crash) tarmac run-off are simply pointless.

The Holy Graal is to balance the dimension of tarmac and gravel. There is no an always good solution. Depending on how’s the corner, what’s the purpose is, what you have to arrest (vehicle or rider), you need to assess risks and design the run-off to suit at best your provisional needs.

But very few racetracks now are designed like I said.

That’s why we see so many tarmac around.

4. Does anybody know where to find the RB6 dimensions, its chassis length in particular?

1. How accurate do you need the numbers to be? All F1 cars are very similar in size due to the regulations. This year they are a little longer than other years (I think) but here’s a good reference:
http://www.formula1.com/inside_f1/rules_and_regulations/technical_regulations/5260/

“As a typical example, the 2007 season Toyota TF107 is 453cm long, 180cm wide and 95cm high.”

1. Okay, so here is my math:
First I completely abandoned any idea of trying to calculate his speeds from the impact point because it is so complex, all the different forces, and so on, it is impossible for anybody to do it.

So I took the only real time footage we got from the crash, and studding it hard I worked out that it takes three and a half frames for him to cover an RB6 car’s length right before the moment of impact, I of course also had to take into account that his front wing was missing, and that he was going in a slight angle.

As Jarno below provided that a healthy bull’s length is 5 meters, and the video was playing 25 f/s. So the calculation is v=5*25/3.5=35.7 m/s, that is 129km/h and 80 mp/h.

As you can see the figures are quite far from those in the article above. But I believe that this figure are much closer to the actual one. In the above article pretty much all of the figures in the equation is an assumption, not to mention that the equation itself is not complete. This equation hove ever is very simple, only the accuracy of my observation is a variable, but even then the margin of error isn’t as big.

But if you ask me, I still wouldn’t want to hit a barrier at 80 mp/h, especially with my feet just a few centimeters from the impact itself as there were no front nose at that point.

1. That matched pretty closely with the figure that Jameson quoted from F1 racing.

5. I think I understand why the FIA prefers concrete, see Alex Wurz’s flips in the 1998 Canadian GP in Ned’s First lap crashes thread. (Thanks Ned) But couldn’t they make the concrete run off areas so it is difficult to regain the track.

6. David Sherwood
6th August 2010, 8:29

OK, so tarmac stays for safety reasons, so how about one of the following, if a car runs off during a race, purely for driver error:

1) An automatic X seconds added to race time

2 Marshall holds car back for X seconds

3)Drive through for using run off

4) Any other ideas!

7. we just need the tarmac to be bordered with grass, like at hockenheim turn 1. The penalty for running wide, is a quick foray onto a (very) narrow pice of grass, which upsets the balance, and although the driver and car can recover unhurt and undamaged, the resultant loss of speed and therefore time is great enough for it never to be the fastest way round the corner. Once over the grass (it’s only about 3 foot wide on that turn in hockenheim) you’re back onto tarmac again and can speed back up. I’d say this loses the drivers at least a second or two, and therefore is never going to yield an advantage – whilst being safer than gravel traps as well.