jnuz73hbn
- 24
- 3
- Homework Statement
- Hello guys,
Consider a spherical, electrically charged body with mass
and charge
, located next to a grounded conducting surface.
The interaction is modeled using the method of image charges.
(1)Determine the maximum radius for which the body is still held against
the surface by electrostatic attraction.
The charged spherical body is now freely suspended in air.
(2) Find out the critical electric field strength of air.
(3)Determine the minimum radius for which the electric field at the
surface of the body does not exceed
- Relevant Equations
- $$
F_{\mathrm{el}}=F_g
$$
$$
r_{\max}=\sqrt{\frac{kq^2}{4mg}}
$$
$$
E_{\mathrm{crit}}=3.0\times10^6\,\mathrm{V/m}
$$
$$
E(r_f\mid r_{\min})=E_{\mathrm{crit}}
$$
I think I'm missing something in the formulas
$$
r_{\max}=\sqrt{\frac{kq^2}{4mg}}
$$
$$
r_{\min}=\sqrt{\frac{k|q|}{E_{\mathrm{crit}}}}
$$
r_{\max}=\sqrt{\frac{kq^2}{4mg}}
$$
$$
r_{\min}=\sqrt{\frac{k|q|}{E_{\mathrm{crit}}}}
$$
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