Physics
Billard ball physics
A few common formulas
velocity = change in distance / change in time
acceleration = change in velocity / change in time
force = mass * acceleration
momentum = mass * velocity
Conservation of Momentum
The total momentum of a system before a collision is equal to the total momentum of a system after a collision. A is Ball A. B is Ball B. vx is velocity x
A.vx = ((A.mass - B.mass) * A.vx + 2 * B.mass * B.vx) / (A.mass + B.mass)
If both objects have the same mass the formula simplifies. We can think of it as A and B swap momentums.
A.vx = 2 * B.mass * B.vx / (A.mass + B.mass)
atan2
Math.atan2
gives you the angle between two vectors.
Subtract the distance between each x and each y coordinate of the vector.
| .(2,4)
| /
| /
| /
| .(1,1)
+----------------+
Math.atan2(1, 3) * 180 / Math.PI
> 18.43494882292201