Answer:
1408.685 KN/C
Explanation:
Given:
R = 0.45 m
σ = 175 μC/m²
P is located a distance a = 0.75 m
k = 8.99*10^9
- The Electric Field Strength E of a uniformly solid disk of charge at distance a perpendicular to disk is given by:
part a)
Electric Field strength at point P: a = 0.75 m
part b)
Since, R >> a, we can approximate a / R = 0 ,
Hence, E simplified relation becomes:
E = σ / 2*e_o
part c)
Since, a >> R, we can approximate. that the uniform disc of charge becomes a single point charge:
Electric Field strength due to point charge is:
E = k*δ*pi*R^2 / a^2
Since, R << a, Surface area = δ*pi
Hence,
E = (k*δ*pi/a^2)
<span>The regioin is titled towqrd the Sun during polar day. (C)
(The same exact thing happens in areas south of the Antarctic Circle
in the southern hemisphere. The only difference is that the whole thing
is spelled better in the South.)</span>
Answer:
Option d
The minimum angular separation between two objects that the Hubble Space Telescope can resolve is 
.
Explanation:
The resulting image in a telescope that will be gotten from an object is a diffraction pattern instead of a perfect point (point spread function (PSF)).
That diffraction pattern is gotten because the light encounters different obstacles on its path inside the telescope (interacts with the walls and edges of the instrument).
The diffraction pattern is composed by a central disk, called Airy disk, and diffraction rings.
The angular resolution is defined as the minimal separation at which two sources can be resolved one for another, or in other words, when the distance between the two diffraction pattern maxima is greater than the radius of the Airy disk.
The angular resolution can be determined in analytical way by means of the Rayleigh criterion.
(1)
Where 
is the wavelength and D is the diameter of the telescope.
Notice that it is necessary to express the wavelength in the same units than the diameter.
⇒ 
Finally, equation 1 can be used.
Hence, the minimum angular separation between two objects that the Hubble Space Telescope can resolve is .
The answer is, "the speed of the current is 5 miles per hour."
To calculate the speed of the current,
let's assume speed of current = xmph. Time taken to travel from one pier to another with the current = 100/(20+x)h
But the time taken to travel from one pier to another with the current, which is given is = 4 hours. So, 4=100/(20+x) 80+4x = 100
4x = 20
x = 5 Thus, the speed of the current is 5 miles per hour.
