Question

In terms of forces, what would the universe be like, qualitatively, if momentum were really p=v/m ?

Answer 1

The world would be really weird. As force is required for change in momentum, and if momentum is inversely proportional to mass, then a lighter body (with lower mass) will see a larger change in velocity as compared to a heavier body. Let us take an example. Take a football and a stone of the size of football which is much heavier than the football. So if we hit both with the same force, the football will move slowly but the stone being much heavier will move much faster. This means if you are fighting with a kid much younger than you, you will probably lose because you being heavier, will fly way if the kid applies force on you.