Would it make a difference, if a car was driven into a wall or another car with the same mass going exactly the same speed?
Are you trying to say that the constants are,
The car you are driving, and the speed you are traveling at.
The object you collided into is the same mass, and traveling at the same speed whether it is shaped as a car or a wall.
With the only difference is that the object you collide into is either shaped as a wall or a car?
The most important part is the *relative* velocity of the car. If you slam the 40mph car into a stationary wall, the relative velocity is 40mph. If that 40mph car hits a car traveling towards it, even if it’s only at 10mph, the relative velocity becomes 50mph (40+10). If the “target” wall is going the same speed as the “target” car, the damage to the hitting car will depend on the elasticity and durability of the wall and how much it collapses compared to the car.
2 cars of same weight going the same speed will have the same damage as one of those cars crashing into a wall going the same speed. Contrary to initial thoughts, the 2 cars crashing will not have damage as going twice the speed. Classic myth busters episode. [collision math](http://warp.povusers.org/grrr/collisionmath.html)
Yes. It depends on what the wall is made out of. Is it made of 16 feet of tissue paper or 1 foot of re-enforced concrete? Also depends on the car? is it a new car designed to bleed of energy via crumple zones or some 1970’s death machine designed to look cool?
Acceleration is a function of time, and soft things give more time for deceleration.
If you’re talking energy then colliding with another vehicle in this example there would be twice energy in the collision than just driving into the wall.