Momentum is mass in motion. Its formula looks like this:
p = mv where p=momentum, m=mass, and v=velocity.
To change an object's momentum, you must give it a force for a length of time.
So, Dp = F Dt.
In most cases, the object's mass does not change, so Dp may be written as: m Dv.
Thus, m Dv = F Dt.
Believe it or not, momentum is actually another form of the equation F=ma. Here's the proof:
F = m Dv/Dt
F Dt = m Dv
But this is what we began with a few lines above! This means it isn't really a new concept at all, just a new way to look at something we've already done. Thank you for recycling. :-)