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irnubcake
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1. Problem1 statement, all variables and given/known data
In the figure particle 1 of charge q1 = -8.13q and particle 2 of charge q2 = +3.63q are fixed to an x axis. As a multiple of distance L, at what coordinate on the axis is the net electric field of the particles zero?
http://img201.imageshack.us/img201/4669/netfieldzeromy7.gif
Electric Field = k|q| / r²
The attempt at a solution
Since it's a point between the two charged particles, let x = the distance between q1 and that point, so the distance between the point and q2 = L - x
http://img157.imageshack.us/img157/990/netfieldzero2xj8.gif
The net electric field = 0,
so -(Electric field due to q1) + (Electric field due to q2) = 0
E1 is negative because q1 is negative, E2 vice versa.
-( k|-8.13q| / x² ) + ( k|3.63q| / (L - x)² ) = 0
Cancelling, etc gives:
4.5x² - 16.26Lx + 8.13L² = 0
quadratic formula gives: x = 0.6L or 3.01L
I got it wrong, I'm also confused about the sign of the electric fields but the quadratic formula won't produce a real solution if both fields were negative or positive.
1. Problem2 statement, all variables and given/known data
Charge is uniformly distributed around a ring of radius R = 2.41 cm and the resulting electric field is measured along the ring's central axis (perpendicular to the plane of the ring). At what distance from the ring's center is E maximum?
Electric Field of Ring = (kqx) / ( (x² + k²) ^ (3/2) )
The attempt at a solution
I attempted to differentiate the equation with respect to x and put E' = 0, but I have two unknowns, x and q, the solution is a real number with no variables.
In the figure particle 1 of charge q1 = -8.13q and particle 2 of charge q2 = +3.63q are fixed to an x axis. As a multiple of distance L, at what coordinate on the axis is the net electric field of the particles zero?
http://img201.imageshack.us/img201/4669/netfieldzeromy7.gif
Homework Equations
Electric Field = k|q| / r²
The attempt at a solution
Since it's a point between the two charged particles, let x = the distance between q1 and that point, so the distance between the point and q2 = L - x
http://img157.imageshack.us/img157/990/netfieldzero2xj8.gif
The net electric field = 0,
so -(Electric field due to q1) + (Electric field due to q2) = 0
E1 is negative because q1 is negative, E2 vice versa.
-( k|-8.13q| / x² ) + ( k|3.63q| / (L - x)² ) = 0
Cancelling, etc gives:
4.5x² - 16.26Lx + 8.13L² = 0
quadratic formula gives: x = 0.6L or 3.01L
I got it wrong, I'm also confused about the sign of the electric fields but the quadratic formula won't produce a real solution if both fields were negative or positive.
1. Problem2 statement, all variables and given/known data
Charge is uniformly distributed around a ring of radius R = 2.41 cm and the resulting electric field is measured along the ring's central axis (perpendicular to the plane of the ring). At what distance from the ring's center is E maximum?
Homework Equations
Electric Field of Ring = (kqx) / ( (x² + k²) ^ (3/2) )
The attempt at a solution
I attempted to differentiate the equation with respect to x and put E' = 0, but I have two unknowns, x and q, the solution is a real number with no variables.
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