Say we have a rectangular hyperbola, of which the right hand part is charged with linear charge density and the left one with .
There is a Rod Lying on the y-axis, with mass , Lenght and its center is kept at . It is charged with, say surface charge density, .
Check out the image.
Find the magnitude acceleration of the rod, as soon as we release it.
If the acceleration of the rod is , Input .
Details And Assumption
Take , and , and
Hyperbola is indefinite.
Find the acceleration in
You can use Wolfram Alpha.
Orginial
Inspired from Steven Sir
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Let the position vector of a point on the vertical wire be:
r p = y j ^
And that on the upper half of the right branch of the hyperbola be:
r h = x i ^ + x 2 − 4 j ^
The vector joining these two points directed away from the wire is:
r = r h − r p
We consider a line element on the wire. The length of the element near the given position vector has charge λ d y . We also consider an arc length element on the hyperbola. The charge on that element near the given position vector is σ d s where d s is the arc length magnitude which is:
d s = d x 1 + ( d x d y ) 2
For the upper half of the right lobe:
d s = d x x 2 − 4 2 x 2 − 4
Applying Columb's law to find electrostatic force at wire element due to the hyperbolic element:
d F = ∣ r ∣ 3 K ( λ d y ) ( σ d s ) r
K = 4 π ϵ o 1
d F = d F x i ^ + d F y j ^
Substituting all expressions and simplifying gives:
d F x = ⎝ ⎜ ⎛ ( ( y − x 2 − 4 ) 2 + x 2 ) 3 / 2 K λ σ 2 x 2 ( x 2 − 4 ) 2 x 2 − 4 ⎠ ⎟ ⎞ d x d y
Similarly an expression for d F y can be computed. Now, the total force on the wire due to the upper half of the right lobe of the hyperbola is:
F x = ∫ − 2 2 ∫ 2 ∞ ⎝ ⎜ ⎛ ( ( y − x 2 − 4 ) 2 + x 2 ) 3 / 2 K λ σ 2 x 2 ( x 2 − 4 ) 2 x 2 − 4 ⎠ ⎟ ⎞ d x d y
Therefore, by symmetry, the force due to the entire right lobe of the hyperbola will be:
F R = 2 F x
Again, by symmetry, the force due to both lobes along the x-direction will be:
F T = 2 F R = 4 F x
Therefore, the acceleration A is:
A = M F T
All forces along Y will evaluate to zero. One can check this by even evaluating the integrals. This step is left out here.
Having obtained F T , the answer comes out to be:
2 0 K A ≈ 4 1 0 . 3 7 3