A ball horizontally hits a wall at 5m/s and bounces back at -5m/s. The total momentum before is 1 kgm/s and after is -1 kgm/s. Is momentum conservation broken down in this example???

Reason???

PLEASE HELP

2 answers

The earth moved a little :)
In fact it moved forward just as much as it moved back when I thew the ball :)
and then caught it !