"HotRod" wrote in message
...
The answer is "A". 100 mph, because

E1=E2 when two cars hit head on which means each car would absorb 50 kmh
of
kinetic energy BUT when a car hits a wall
E1 is divided in 1/2, 1/2 going to the wall and 1/2 to the car. It's all
in
the wording of the question

i'm too lazy to search for the OP.
but i have to add, are the 2 vehicles identical with 0 wind on level ground?
or are you talking about 2 objects in a vacuum colliding at equal mass and
velocity?

did you know that a vehicle without a built in cup holder has a higher
occupant survival rate than vehicles with multiple built-in cup holders?

-a|ex