- #1
Feldoh
- 1,342
- 3
We're learning about a systems center of mass and have:
[tex]F_{net} = Ma_{com}[/tex]
But I having a problem understanding why the net force is only from external forces? Is it because internal forces follow Newtons third law so the net force from internal forces is 0? If that's the case then take for example a bottle-rocket firework. Once it explodes is we ignore air resistance (so the only force is gravity) would the fragments of the firework still fall with the same trajectory since the internal forces are 0?
[tex]F_{net} = Ma_{com}[/tex]
But I having a problem understanding why the net force is only from external forces? Is it because internal forces follow Newtons third law so the net force from internal forces is 0? If that's the case then take for example a bottle-rocket firework. Once it explodes is we ignore air resistance (so the only force is gravity) would the fragments of the firework still fall with the same trajectory since the internal forces are 0?