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- Thread starter Mohamad
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Yes, the typical assumption with "stick together" is a head-on collision, ignoring the possibility of a resulting rotation. But a literal reading of the problem statement in #1 above allows the possibility.

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What collision scenario do you have in mind ?

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Clearly you do not understand the basic definitions of elastic and inelastic collision. You could at least look those up before proceeding.Mohamad said:Summary:elastic or inelastic collision?

If the initial kinetic energy is equal to the final kinetic energy where two objects that collide stick together, this collision is elastic or inelastic?

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I thought we weren't supposed to spoon-feed the answers.HallsofIvy said:giventhat kinetic energy is conserved so this has to be an elastic collision.

I had already asked him to look up the defintions so that he could figure that out for himself.

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So your scenario is contradictory. Either the bodies don't stick together, or the kinetic energy isn't conserved, you can't have both. OR there are external forces in play.

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Or the objects were spinning just right so that they could latch onto one another without dissipating any energy. They can then spin about one another, each retaining its original (and rotational) kinetic energy in the combined center-of-momentum frame.Delta2 said:So your scenario is contradictory. Either the bodies don't stick together, or the kinetic energy isn't conserved, you can't have both. OR there are external forces in play.

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The way I interpreted "stick together" is that they have exactly the same velocity after the collision. In the scenario you describe they don't have the same velocity after the collision (spinning about one another means they have opposite and equal velocities (in the best scenario) if I understand it properly)jbriggs444 said:Or the objects were spinning just right so that they could latch onto one another without dissipating any energy. They can then spin about one another, each retaining its original (and rotational) kinetic energy in the combined center-of-momentum frame.

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Yes, the typical assumption with "stick together" is a head-on collision, ignoring the possibility of a resulting rotation. But a literal reading of the problem statement in #1 above allows the possibility.Delta2 said:The way I interpreted "stick together" is that they have exactly the same velocity after the collision. In the scenario you describe they don't have the same velocity after the collision (spinning about one another means they have opposite and equal velocities (in the best scenario) if I understand it properly)

An elastic collision is a type of collision between two objects where there is no loss of kinetic energy. This means that the total kinetic energy of the system before and after the collision remains the same.

An inelastic collision is a type of collision between two objects where there is a loss of kinetic energy. This means that the total kinetic energy of the system before the collision is greater than the total kinetic energy after the collision.

To determine if a collision is elastic or inelastic, you can calculate the coefficient of restitution (e) using the formula e = (relative velocity of separation)/(relative velocity of approach). If the value of e is equal to 1, the collision is elastic. If the value is less than 1, the collision is inelastic.

A real-life example of an elastic collision is when two billiard balls collide on a pool table. A real-life example of an inelastic collision is when a car collides with a wall, as some of the kinetic energy of the car is lost to deformation and heat.

The concept of elastic and inelastic collisions is important in science because it helps us understand and predict the behavior of objects in motion. It is also crucial in fields such as engineering and physics, where the conservation of energy is a fundamental principle. Additionally, this concept is used in many practical applications, such as in designing safer car bumpers or creating more efficient pool balls.

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