Answer:
84.82N/C.
Explanation:
The x-components of the electric field cancel; therefore, we only care about the y-components.
The y-component of the differential electric field at the center is
.
Now, let us call
the charge per unit length, then we know that
;
therefore,
![$dE = \frac{k \lambda R d\theta }{R^2} sin(\theta )$](https://tex.z-dn.net/?f=%24dE%20%3D%20%5Cfrac%7Bk%20%5Clambda%20R%20d%5Ctheta%20%7D%7BR%5E2%7D%20sin%28%5Ctheta%20%29%24)
![$dE = \frac{k \lambda d\theta }{R} sin(\theta )$](https://tex.z-dn.net/?f=%24dE%20%3D%20%5Cfrac%7Bk%20%5Clambda%20%20d%5Ctheta%20%7D%7BR%7D%20sin%28%5Ctheta%20%29%24)
Integrating
![$E = \frac{k \lambda }{R}\int_0^\pi sin(\theta )d\theta$](https://tex.z-dn.net/?f=%24E%20%3D%20%5Cfrac%7Bk%20%5Clambda%20%20%20%7D%7BR%7D%5Cint_0%5E%5Cpi%20sin%28%5Ctheta%20%29d%5Ctheta%24)
![$E = \frac{k \lambda }{R}*[-cos(\pi )+cos(0) ]$](https://tex.z-dn.net/?f=%24E%20%3D%20%5Cfrac%7Bk%20%5Clambda%20%20%20%7D%7BR%7D%2A%5B-cos%28%5Cpi%20%29%2Bcos%280%29%20%5D%24)
![$E = \frac{2k \lambda }{R}.$](https://tex.z-dn.net/?f=%24E%20%3D%20%5Cfrac%7B2k%20%5Clambda%20%20%20%7D%7BR%7D.%24)
Now, we know that
![\lambda = 3.0*10^{-9}C/m,](https://tex.z-dn.net/?f=%5Clambda%20%3D%203.0%2A10%5E%7B-9%7DC%2Fm%2C)
![k = 9*10^9kg\cdot m^3\cdot s^{-4}\cdot A^{-2},](https://tex.z-dn.net/?f=k%20%3D%209%2A10%5E9kg%5Ccdot%20m%5E3%5Ccdot%20s%5E%7B-4%7D%5Ccdot%20A%5E%7B-2%7D%2C)
and the radius of the semicircle is
![\pi R = 2.0m,\\\\R = \dfrac{2.0m}{\pi };](https://tex.z-dn.net/?f=%5Cpi%20R%20%3D%202.0m%2C%5C%5C%5C%5CR%20%3D%20%5Cdfrac%7B2.0m%7D%7B%5Cpi%20%7D%3B)
therefore,
![$E = \frac{2(9*10^9) (3.0*10^{-9}) }{\dfrac{2.0}{\pi } }.$](https://tex.z-dn.net/?f=%24E%20%3D%20%5Cfrac%7B2%289%2A10%5E9%29%20%283.0%2A10%5E%7B-9%7D%29%20%20%20%7D%7B%5Cdfrac%7B2.0%7D%7B%5Cpi%20%7D%20%7D.%24)
![$\boxed{E = 84.82N/C.}$](https://tex.z-dn.net/?f=%24%5Cboxed%7BE%20%3D%2084.82N%2FC.%7D%24)
Answer:
c.Law
Explanation:
i think you must learn and write however good luck
No they don't. Incident rays parallel to the axis of a concave mirror
reflect from the mirror's surface and converge at its focal point.