"Harry K" wrote in message
om...
(Borrall Wonnell) wrote in message
. com...
You *are* bored.

I'm bored so will put forward this one to see what happens:

2 cars of equal mass crash head on at 50 mph. Both drivers will feel
an impact equal to crashing into a solid object at:
a. 100 mph
b. 50 mph
c. Other


Hmmm...is this a trick question? It's been a while....

Look at billard balls. When the cue ball strikes a stationary ball
head-on (ignoring spin), the stationary ball beings moving and the cue
ball stops dead.
Let's say the cue ball was travelling at 50mph. Effectively it has
hit a 'brick wall' at 50mph since it stopped dead. So if the second
ball was travelling in the opposite direction at the same speed, the
cue ball would not just stop, but 'bounce' and travel at 50mph in the
oppposite direction. Effectively hitting a wall at 100mph.

Correct so far? Maybe, maybe not. At this point I don't care.

Now, that's all well and good but cars are a different story.
Collisions are not perfectly elastic due to crumple zones and other
losses. Assuming both cars 'stick' together after the collision, the
wreck will remain stationary at the point of impact. In this case,
each driver will feel the effect of hitting a wall at 50mph (i.e. each
goes from 50mph to 0mph).

If the cars 'bounce' off each other, then the impact will be somewhere
between 50 and 100mph.

Of course, dont forget about seat belts and air bags which may save
their lives....if that gas leak didn't engulf the vehicles in flames
first.

Do you actually have an answer to this 'problem'?

Yes, it is 50mph give or take allowing for crumple zones etc. I first
saw this on in sophmore physics class in HS back in 1951. Quite a
discussion and got into involved math etc but it all comes down to a
simple mind excercise.

From what speed did each driver stop?? 50mph.

so the impact is the same whether you hit a wall, a 50mph car, or a
100000mph car.

i dont buy it.

randy