- #1
MystiqThunder
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1. Homework Statement
Two electrons start at rest with a separation of 5.0*10-12m. Once released, the electrons accelerate away from each other. Calculate the speed of each electron when they are a very large distance apart.
ΔEK+ΔEE=0
Okay so I know that:[/B]
mass of electron = 9.109*10-31 Kg
q = -1.60*10-19 C
k = 8.99*109
v1 = 0 m/s
r1 = 5.0*10-12 m
My process:
ΔEK+ΔEE=0
-ΔEE=ΔEK
-[kq1q2(1/r2-1/r1)]=½m(v2-v1)2
√[{-2(kq1q2(1/r2-1/r1)}/m]=v2
√[{-2(8.99*109)(-1.60*10-19)2(0-1/5.0*10-12)/(9.109*10-31)]=v2
1.0*107=v2
Is this correct?
Hopefully that shows it well, if not here is a picture (I write small, probably can't make out much):
EDIT: Looks like pic is a no show
Two electrons start at rest with a separation of 5.0*10-12m. Once released, the electrons accelerate away from each other. Calculate the speed of each electron when they are a very large distance apart.
Homework Equations
ΔEK+ΔEE=0
The Attempt at a Solution
Okay so I know that:[/B]
- The Electric force is in the same direction as the displacement, which means kinetic energy is increasing and electric energy is decreasing (ΔEK=-ΔEE)
- As they move to a really far distance, the change in electric energy is equal to 0 - EE1 as anything divided by infinity is equal to zero
mass of electron = 9.109*10-31 Kg
q = -1.60*10-19 C
k = 8.99*109
v1 = 0 m/s
r1 = 5.0*10-12 m
My process:
ΔEK+ΔEE=0
-ΔEE=ΔEK
-[kq1q2(1/r2-1/r1)]=½m(v2-v1)2
√[{-2(kq1q2(1/r2-1/r1)}/m]=v2
√[{-2(8.99*109)(-1.60*10-19)2(0-1/5.0*10-12)/(9.109*10-31)]=v2
1.0*107=v2
Is this correct?
Hopefully that shows it well, if not here is a picture (I write small, probably can't make out much):
EDIT: Looks like pic is a no show