View Full Version : Just wondering IV

22-01-2010, 09:04:35
This one is for the physicicsisists amongst us:

I was driving on the motorway yesterday when my windshield was hit by a small stone, creating a lovely star in my car window.
Afterwards I was wondering about bouncing litlle stones on motorways. If a small stone is cast up by a car doing about 100 km/h, and it hits a windshield of another car, also doing a 100 km/h, at some angle, what sort of trajectory and speed does it follow? Does it more or less bounce up and down and get thrown up in the air now and then, or does it travel at incredible speed across the motorway, gaining more and more momentum with every windshield it hits?

I like to think of a litle stone, traveling acros the motorway, jumping from windshield to windshield, ending up hundreds of kilometres away from home.
"Papa was a bouncing stone, where ever he laid his head, was his home!!"

22-01-2010, 09:10:12
The problem is it all depends on what "at some angle" is and how fast and at what trajectory it's cast up by the car in the first place. As well as where it hits and what happens to the glass it hits...

but the little stone bouncing for hundreds of kilometers from windshield to windshield sounds highly unlikely.

22-01-2010, 09:14:57
typical boring physisist answer :(

22-01-2010, 09:28:12
Unless the magical stone fairy comes along to carry the stone to it's new home.

Cheshire Cat
22-01-2010, 09:44:19
Drekman, you could create a tiny gravel stone with GPS embedded, and scatter a lot of them on the highway

then you'll be able to track their path and speed
it might even earn you a Nobel


22-01-2010, 10:18:38
Now that's a worthy experiment!

22-01-2010, 12:24:36
You could probably get government funding for the research.

22-01-2010, 14:32:30
Get a government research grant for the science and an arts council grant for the art aspect.

22-01-2010, 14:54:46
Finally this place comes up with something useful. :beer:

22-01-2010, 15:32:08
And I want the BBC Natural World camera team to film all the live testing.

22-01-2010, 15:40:53
Finally this place comes up with something useful. :beer:

It was bound to happen eventually.

22-01-2010, 15:51:52
CG is almost literally the monkeys with typewriters thing.

22-01-2010, 16:08:52
Now, let's get to the really important part: who's gonna play who in the movie?

22-01-2010, 16:13:33
Just need one actor to play Keith don't we?

22-01-2010, 16:14:53
Yeah. Which actor is the gayest twat of all time?

22-01-2010, 17:19:58
Tom Cruise is pretty god damned gay and he's a twat.

22-01-2010, 17:21:21
Kevin Spacey.

Cheshire Cat
22-01-2010, 18:59:58
Brian Keith (http://www.imdb.com/name/nm0001417/)

(...it's a Family Affair (http://en.wikipedia.org/wiki/Family_Affair)!)

Lazarus and the Gimp
22-01-2010, 20:52:55
I like to think that, instead of being flipped up by tyres, the stones get batted back and forth by the windscreens of cars like a game of tennis, and that some stones on busy roads haven't touched the ground in years.