Explosion momentum
Just like in any other collision, the total momentum and kinetic energy of a closed system is conserved in an explosion.
However: the type of energy may change in an explosion. For example:
- The chemical energy stored in the explosive material may be converted into kinetic energy of the fragments of the explosion.
- The kinetic energy of the fragments may be converted into heat and sound energy as they collide with each other and with the surroundings.
In short, it may seem like some kinetic energy is ‘lost’ or ‘gained’, because it’s converted from one type of energy to another.
In reality, the total energy of the system stays the same.
flashcards
| Question | Answer |
|---|---|
| In an explosion within a closed system, what two physical quantities are always conserved? | Total momentum and total kinetic energy are conserved. However, the type of energy may change (e.g., chemical energy converted to kinetic energy), so while total system energy is conserved, kinetic energy may appear to be “lost” or “gained” from one form to another. |
| What happens to the chemical energy stored in the explosive material during an explosion? | The chemical energy stored in the explosive material may be converted into the kinetic energy of the fragments of the explosion. |
| What may happen to the kinetic energy of the explosion fragments as they collide with each other and the surroundings? | The kinetic energy of the fragments may be converted into heat and sound energy as they collide with each other and with the surroundings. |
| Why might it seem like kinetic energy is “lost” or “gained” in an explosion? | It may seem like kinetic energy is “lost” or “gained” because it is converted from one type of energy to another (e.g., from chemical to kinetic, or from kinetic to heat/sound). In reality, the total energy of the system remains the same. |