Question

In inelastic collisions, when a car that is initially moving collides into a car initially still I know that both cars will move in the direction of the initially moving car at a slower velocity, But would I say momentum has been transferred from car 1 to car 2 or velocity has been transferred from car 1 to car 2. Because obviously, mass is not transferred. And if the initially moving car is more massive than the still car, or vice versa, would it still apply that 1/2 of the initially moving car's velocity gets transferred to the still car or would it be a different fraction of its velocity since masses are different.

Answer 1

First of all let us understand what is inelastic collision , it is a type of collision in which kinetic energy is not conserved due to the action of internal friction which means not all of the kinetic energy of the car which collides is transferred to the car to which it collides , only some part of it is transferred , where as rest is converted to heat , vibrations , sound energy.

Now , coming to your question if the momentum or the velocity is transferred , NO neither of them are transferred , but the as mentioned above some part of the kinetic energy is transferred and that transferred energy gives rise to new velocity which sets the car in motion and this motion gives rise to momentum.

And if the initial car is massive , when it collides with a still car not half of the velocity is transferred the fraction may vary depending upon the mass of the car its final velocity and in what way it  collides. Since you have assumed  that the car is massive then the heat , sound and vibrations generated due to the collision will also be large and again only a small part of the kinetic energy will be transferred .