# What decides the trajectory of shrapnel upon explosion?

What are the factors that govern over the path that shrapnel and/or other particles follow upon explosion of explosives(the ones that are planted i.e. stationary ones) etc. Is it possible to predict the path of all the particles ? Also is it possible to make the particles move in desired directions ?

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Please define the following: 1) explosion of a static object? 2)symmetry of the exploding body prior to explosion? 3) homogeneity of the material which is not consumed in the explosion? There are plenty of guided-charge designs. Heck, a rifle bullet is one such! – Carl Witthoft Dec 26 '13 at 16:44
en.wikipedia.org/wiki/Gun – DumpsterDoofus Dec 26 '13 at 20:18

I think only one factor governs the path of shrapnels : Conservation of Momentum.

Even when the explosive is planted, the principle of conservation acts, for the total sum of displacement of shrapnels would then equal Zero. Thats why for a stationary explosive, shrapnels scatter in all directions.

It is not "impossible" to predict the path of all particles theoretically. Practically, unless we have a special explosive that defragments along certain parts I dont think its possible to keep account of so many shrapnels, for example : a real life grenade.

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Keeping account of the multitude of particles is definitely possible, it may be tedious and time consuming, but definitelg possible. – Rijul Gupta Jan 13 '14 at 15:07
true that. it was just a personal opinion. – Sagnik Jan 13 '14 at 15:11

The path is governed by tragectory, initial velocity, collisions, air resistance, gravity and deflection from the ground.

The trajectory is decided by initial position.

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To predict the path of shrapnels one needs to perfectly know how the bomb is built i.e. how it will defragment. So it's theoretically possible but only if we're given the initial conditions.

As Sagnik pointed out what you know is that the total momentum will be conserved. So for a "stationary" bomb the total momentum will be 0, for fireworks the global motion of the shrapnels will be parabolic (if we neglect air resistance).

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