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# Conservation of Momentum: Masses and Speeds

The momentum p is calculated as mass * speed. The formula for the above calculation is: _{1} * v_{b} = m_{1} * v_{a} + m_{2} * v_{2}

Example: a white billiard ball with a weight of 180 grams hits another ball with a weight of 170 grams at a speed of 15 km/h. When the white ball completely releases its momentum, the other ball then has a speed of 15.9 km/h. If the cue ball is still moving at 5 km/h after the collision, the speed of the other ball is 10.6 km/h.

The direction in which a pushed object moves can differ from the direction of the object hitting it. This is particularly evident with billiard balls when they do not collide in the middle. The angle of the movement depends on the angle at which the point of impact is from the original movement. If the pushed object moves on with a different angle, the angle of the further movement of the object hitting it also changes, and the object then moves in a different direction. The three impulses can be calculated like forces.

Physics commonly uses SI units. Here is a calculator to convert units.