Given Electric Potential Function Find where field is zero.

AI Thread Summary
The electric potential function is given as V = 13x² - 16x + 59. The electric field is determined by the negative gradient of this potential, leading to the equation Ex = -dV/dx = - (26x - 16). The correct derivative yields Ex = 13x - 16, which must be set to zero to find the position where the electric field is zero. Solving the equation 13x - 16 = 0 gives x = 1.23 m. The discussion emphasizes the importance of accurately performing derivatives in physics calculations.
disfunctlguru
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1. The electric potential in a certain region is:
V = ax2 +bx +c

where a = 13V/m2
b = -16V/m
c = 59 V

Determine the postion where the electric field is zero. Answer in units of m.

Homework Equations



E = -\nablaV

The Attempt at a Solution



I know that the Electric Field is the negative gradient of the potential function. I then find that the partials with respect to y and z are zero. Then I find the partial with respect to x is: Ex=-13x+16
Then find the zero to be about 1.23. But it is apparently incorrect. Any help would be appreciated.
 
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disfunctlguru said:
Then I find the partial with respect to x is: Ex=-13x+16
Redo that derivative.
 
Well the actual partial deriv. is 13x-16. Then I took the opposite to be used as the function of E.
 
disfunctlguru said:
Well the actual partial deriv. is 13x-16. Then I took the opposite to be used as the function of E.
Double check that.
disfunctlguru said:
1. The electric potential in a certain region is:
V = ax2 +bx +c
What's the derivative of that function?
 
Thanks, I can't believe I can do some other complex integration etc and mess up a simple deriv... mind blowing.
 
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