On Wed, 5 May 2010 21:34:52 -0700, "Artemus" wrote
the following:


"Existential Angst" wrote in message
...
Awl --

Are two cars hitting each other at 50 mph the same as 1 car hitting an
immovable wall at 100 mph?

Short answer = no.

Longer answer. If the 2 cars are the same mass(weight) they will both
come to a stop at the point of the collision. Now imagine a brick wall
at that point and each car slams into a side. Each car goes from 50mph
to zero in both cases.

Now only use 1 car and the brick wall. That car still goes from 50mph
to 0mph.

In terms of physics each car has energy = 1/2mv^2, where m = mass
and v= velocity. For 1 car going 50mph: 1/2m(50)^2 = 1250m units
The total energy for both cars is 2500m units.
For 1 car going 100mph its energy is 1/2m(100)^2 = 5000m units.
Clearly not the same thing.
Art

Close, but no cigar, since you assumed vehicles of equal mass. If you
have a Chebby Geo meet a Suburban, it will be closer to 75mph Geo vs
25mph Suburban. The doubled mass of the heavier vehicle will keep
pushing until it shoves the Geo a wee bit more. You'd definitely
rather be an occupant in the larger, heavier vehicle.

Sister Mary Elizabeth says "ClaaaaaaaaaaAss!"
This is demonstrable in a vise. Chuck a sheet of 1/4" steel in it and
get a common ball peen hammer on one side and a 3# sledge on the
other. Hold the sledge against the strip of steel and hit the other
side with the ball peen. Reaction: small movement of the sledge. Now
hold the ball peen against the steel and hit it with the sledge.
Reaction: The ball peen hammer goes flying.

--
All national institutions of churches, whether Jewish, Christian,
or Turkish, appear to me no other than human inventions, set up
to terrify and enslave mankind, and monopolize power and profit.
--Thomas Paine