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So let's say for example I have an object with 5kg of mass.

It explodes with a force of 500N.

The object fragments into four fragments: a 0.5kg, a 1kg, a 1.5kg and a 2kg object.

What force does each of those fragments have (and thus what acceleration)?

My assumption is that it will get a percentage of the force relative to the percentage of the mass. So the 1kg fragment is 1/5th of the original mass thus it gets 1/5th of the force?

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up vote 1 down vote accepted

It explodes with a force of 500N.

This sentence is nonsensical. It can explode and release some energy. It can also explode and impart a very high force onto the fragments (which sill be different for each fragment) for a very short time interval.

Once the explosion takes place, the fragments will not accelerate (they may decelerate due to air drag, and of course gravity accelerates them). They only accelerate at the moment of the explosion, and this acceleration is highly dependent on the mechanics of the explosion.

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Okay to rephrase: if the explosion has 500J of energy, what kind of acceleration will each fragment get? – R Bowen May 17 '13 at 6:10
@RBowen: highly dependent on the mechanics of the explosion. We usually assume that the acceleration is near-infinite and occurs only for a very short period of time. (See: ) – Manishearth May 17 '13 at 6:13
Well my task is to simulate an explosion, not of any particular type, it just has to be an object that explodes. My only problem was how much acceleration to give each fragment. – R Bowen May 17 '13 at 6:40
@RBowen: It could be anything you want. Remember, the acceleration is only for a very small moment, so what is more important is the final velocities. Make sure you conserve momentum and energy when deciding the velocities. – Manishearth May 17 '13 at 6:42

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