# Particle A and particle B are held together with a compressed spring between them. When they are released, the spring pushes them apart ?

Particle A and particle B are held together with a compressed spring between them. When they are released, the spring pushes them apart and they then fly off in opposite directions, free of the spring. The mass of A is 5.00 times the mass of B, and the energy stored in the spring was 60 J. Assume that the spring has negligible mass and that all its stored energy is transferred to the particles. Once that transfer is complete, what are the kinetic energies of (a) particle A and (b) particle B?

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And if you move this to Physics I'll work it. @Amy's answer isn't quite right.

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• The spring exerts the same magnitude of force on each particle for the same amount of time.

Thus, in total it imparts the same magnitude of momentum to each particle.

Particle A has 5 times the mass of B, so A has 1/5 the speed of B.

Particle A has 1/5 the kinetic energy of B, or 1/6 of the total energy.

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