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- 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?
Clearly you do not understand the basic definitions of elastic and inelastic collision. You could at least look those up before proceeding.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?
I thought we weren't supposed to spoon-feed the answers.An "elastic collision" is, by definition, one in which kinetic energy is conserved. Since, in an inelastic collision, we don't have the "conservation of kinetic energy" equation, we need another condition to solve for the speeds after the collision. Often that is given by requiring that the two objects stick together, but that is not necessary. We can have an inelastic collision in which the two objects do not stick together and we can have an elastic collision in which the two objects do stick together. Here, we are given that kinetic energy is conserved so this has to be an elastic collision.
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.So your scenario is contradictory. Either the bodies don't stick together, or the kinetic energy isn't conserved, you cant have both. OR there are external forces in play.
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)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.
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.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)