Conservation of Momentum Conservation of momentum, in short, is the idea that in an isolated system all momentum is conserved. What this means in the case of an explosion is that all of the momentum will be conserved by expelling  fragments in all directions around it based on the initial explosion forces. At the end, the vector sum of  all of the individual fragments from the explosion will be equal to zero. This means that the total  momenta of the system will equal the initial momenta sum. We can take advantage of this fact by using  it to create things such as engines, guns, scientific testing and more!