Finding speed of two electrons initially at rest

[ozbii]

Homework Statement

Two electrons start at rest with a separation of 5.0 x 10^-12 m. Once released, the electrons accelerate away from each other. Calculate the speed of each electron when they are a very large distance apart (Ee = 0).

Homework Equations

E_E = kQq/r
E_k = (1/2)mv²

The Attempt at a Solution

E_E2 - E_E1 = - (E_k2 - E_k1)
- E_E1 = - E_k2
(kq²) / r = (1/2)mv²
v = sqrt[ 2(8.99 x 10⁹)(-1.6 x 10^-19)² / (9.11 x 10^-31)(5.0 x 10^-12) ]
v ≅ 1.0 x 10⁷ m/s

The answer is apparently 7.1 x 10⁶ m/s
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[TSny]

Hello, and welcome to PF!

Do both electrons end up with some kinetic energy? Did you take that into account?

 

[ozbii]

Hello, and welcome to PF!Do both electrons end up with some kinetic energy? Did you take that into account?

Thanks for replying!
Oh I don't think I did. So it would be Ee1 = (1/2)mv^2 + (1/2)mv^2.

 

[TSny]

Yes. Are you assuming that the two electrons end up with the same speed? Can you justify that?