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I am having trouble with the following linear momentum problem:

A has a mass mA = 9.11x10^31 kg

B has a mass mB = 1.67x10^-27 kg

They are attracted to each other by some electrical force.

Say they are released from rest with a distance between them of Di = 3.0x10^-6 m

When their distance is decreased to D = 1.0x10^-6 m, what is the ratio of

a) their linear momentums

b) speeds

c) kinetic energies

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i know:

p = mv

so for a)

I am looking for: Pe/Pp

mAvA/mBvB

I have mA and mB, but not vA or vB

I know that they are released from rest, but how do you find vA and vB?

Can I use V^2 = Vi^2 + 2a(D-Di) ? If so, how do I find the a?

Thanks. I just need to be pointed in the right direction.

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# Homework Help: Linear momentum

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