When two billiard balls collide head-on with one at rest, the moving ball will transfer its momentum to the stationary ball causing it to move in the same direction with the same speed.
The speed and direction of the moving ball after the collision is determined by the mass and velocity of both balls before the collision, as well as the angle at which they collide.
No, the collision between two billiard balls is not perfectly elastic. Some energy is lost due to friction and deformation of the balls, resulting in a decrease in the speed of the moving ball after the collision.
If the stationary ball has a greater mass, the speed of the moving ball after the collision will be lower compared to if the stationary ball had a smaller mass. This is because the heavier ball will absorb more of the momentum from the collision.
Yes, the direction of the moving ball can change after the collision depending on the angle at which the balls collide. If the angle is not directly head-on, the moving ball may bounce off at a different angle.