This model illustrates the laws of conservation of mechanical energy and linear momentum using the concept of elastic collision as an example. You can change the initial speed v of the flying ball, the distance d and the masses m1 and m2 of both balls. After the balls collide, you will see a new diagram that displays the balls? momentum, as well as the values of reflection angles, velocities, kinetic energies and projections onto the coordinate axes of the balls? linear momentums. Note that the sum of the kinetic energies of the balls is equal to the initial kinetic energy of the flying ball. Also, note that the total numeric value of the balls? linear momentums after the collision (as projected on the X-axis) is equal to the initial linear momentum of the flying ball, while the sum of the linear momentums on the Y-axis equals zero. Also, note that when two balls of equal mass undergo an elastic collision, they always fly away at the right angle to each other.