Heads up - Fifth Gear review on 14th Oct.

Sorry cjfp, you must have been asleep when they covered kinetic energy at school. It's KE which does the damage.

The KE of a car of mass M and velocity V is 0.5*M*V^2

For a car travelling at 2V, the KE is 2*M*V^2

For two cars travelling at V, the total KE is M*V^2.

So, the energy in that car hitting a wall at 120 is twice that of two cars colliding head-on at 60 each. The damage at 120 is much more severe because the greater energy is dissipated through a smaller mass. Truth is though, neither is survivable.

I wasn't asleep as I managed to get A level A grade - However, that was a fair few years ago (and needless to say I don't actively use physics calcs in my day to day activities very much) and therefore I'm happy (grrr) to stand corrected.

I have never seen a brick wall traveling at 120 mph (or 60).
So it's not a fair test, to say it's like two cars crashing head on.

Regardless of the physics of the speeds, that video should become compulsory viewing for all driving test candidates as an illustration of what the results of a head-on collision at LESS then the national speed limit. The results of the Focus (which is a pretty high tech car, safety wise) having a head-on at 70mph with another doing the same don't bear thinking about, let alone at the speeds that some people seem to think are quite acceptable on most A roads in the UK.

(15-10-2011 08:18am)mark_n Wrote:  I think the Evoque was seriously impressive coming down that 1:1 slope. The short overhangs really work. I wonder if it would get up it?

That 1:1 slope certainly looked a bit steeper than 45 degrees!

I have no doubt at all that it would go up....

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(15-10-2011 11:13am)XFullFatTim Wrote:  Regardless of the physics of the speeds, that video should become compulsory viewing for all driving test candidates as an illustration of what the results of a head-on collision at LESS then the national speed limit. The results of the Focus (which is a pretty high tech car, safety wise) having a head-on at 70mph with another doing the same don't bear thinking about, let alone at the speeds that some people seem to think are quite acceptable on most A roads in the UK.

Fully agree Tim...all young males especially should eb made to watch and see a fire and rescue simulation. It is one reason I drive RR...having seen friends who are only alive because they were in thrie RR (which was totalled) when some young sprog decided to mump the red lights at 70 mph...

Direct link to full program here: http://www.channel5.com/shows/fifth-gear...ode-11-174

(15-10-2011 11:13am)XFullFatTim Wrote:  Regardless of the physics of the speeds, that video should become compulsory viewing for all driving test candidates as an illustration of what the results of a head-on collision at LESS then the national speed limit. The results of the Focus (which is a pretty high tech car, safety wise) having a head-on at 70mph with another doing the same don't bear thinking about, let alone at the speeds that some people seem to think are quite acceptable on most A roads in the UK.

Agreed. It should also be shown to those who lose their licence through a speed related offence, along with other shocking videos!
That said there are those that will never take note no matter what!

(15-10-2011 11:13am)XFullFatTim Wrote:  Regardless of the physics of the speeds, that video should become compulsory viewing for all driving test candidates as an illustration of what the results of a head-on collision at LESS then the national speed limit.

Ignore the laws of physics if you want to, but they still apply. The carnage we saw of a car driving into a brick wall at 120 mph is equivalent to two cars colliding head-on at 84 mph each, which, so far as I know is NOT LESS than the national speed limit, even in Bonnie Scotland.

Mark, I wasn't implying to disregard physics, it was the discussion in the threads above.
Sorry my maths / physics is a bit rusty 37 years after leaving school, how do you arrive at the speed of 84mph - which isn't that far off the speed that many drivers seem to consider to be the enforceable speed limit - 80mph.