- #1

ChiralSuperfields

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- Homework Statement
- Four identical particles, each having charge ##q## and mass ##m##,

are released from rest at the vertices of a square of side ##L##.

How fast is each particle moving when their distance from

the center of the square doubles?

- Relevant Equations
- ##U_E = qV ##

##KE = \frac{mv^2}{2} ##

I tried solving the problem above by using conservation of energy

##U_{Ei} = U_{Ef} + KE ##

##\frac{4k_eq^2}{\sqrt{2}L} = \frac{4k_eq^2}{2\sqrt{2}L} + 4(\frac{mv^2}{2}) ##

##\frac{2k_eq^2}{\sqrt{2}L} = 2mv^2 ##

## v = \sqrt {\frac {k_eq^2}{\sqrt{2}Lm}} ##

However, the solutions solved the problem differently

Would anybody please tell me what I have done wrong?

Many thanks!

##U_{Ei} = U_{Ef} + KE ##

##\frac{4k_eq^2}{\sqrt{2}L} = \frac{4k_eq^2}{2\sqrt{2}L} + 4(\frac{mv^2}{2}) ##

##\frac{2k_eq^2}{\sqrt{2}L} = 2mv^2 ##

## v = \sqrt {\frac {k_eq^2}{\sqrt{2}Lm}} ##

However, the solutions solved the problem differently

Would anybody please tell me what I have done wrong?

Many thanks!