Abullet with a mass of 8.0 g and a speed of 650 m/s is fired at a block of wood with a mass of 0.250 kg. the block rests on a frictionless surface, and is thin enough that the bullet passes completely through it. immediately after the bullet exits the block, the speed of the block is 12 m/s. what is the speed of the bullet when it exits the block

Is a  vector quantity  that refers to "the rate at which an object changes its position." imagine a person moving rapidly - one step forward and one step back - always returning to the original starting position. while this might result in a frenzy of activity, it would result in a zero velocity. because the person always returns to the original position, the motion would never result in a change in position. since velocity is defined as the rate at which the position changes, this motion results in zero velocity. if a person in motion wishes to maximize their velocity, then that person must make every effort to maximize the amount that they are displaced from their original position. every step must go into moving that person further from where he or she started. for certain, the person should never change directions and begin to return to the starting position.

As newton's first law states a object in motion stays in motion