A chicken and a sparrow collide in mid air

[spectroscopy]

The chickens heavier obviously, same speed, what happens when they collide, do they drop ? Or does the chicken keep going forward and the sparrow back ? What law of physics is this ? Cheers

[paulsterio]

It depends on many factors, depending on whether they will stick together, but both the chicken and the sparrow will end up moving in the direction which the chicken was originally moving.

This is conservation of momentum.