Why is force= mass x acceleration instead of velocity?

In your train example, if the train is traveling at a constant velocity of 100 mph, the acceleration is zero, and by Newton's second law the net force is also zero. But this has no ... The resulting force of said train would depend on the Mass/density of the opposing object- newtons second law. read more

Force=Mass×Acceleration is only valid when mass is a constant. {F=d(m.v)/dt}=> {F=m.(dv/dt)} And dv/dt is rate of change of velocity wrt. time hence acceleration. This is how force is related to acceleration (rate of change of velocity) and not just velocity itself. Impulse is change in linear momentum given by integrating force over a given time. read more

Relation is : Force = (Mass * velocity)/time. F = d(p)/dt *If the mass of object is constant and velocity is increasing/decreasing with time, then. d(p)/dt = m d(v)/dt. And if mass is changing with time but velocity is constant, then. d(p)/dt = v d(m)/dt. read more