The electric field produced by a large flat plate with uniform charge density on its surface can be found by using Gauss law, and it is equal to

where

is the charge density

is the vacuum permittivity
We see that the intensity of the electric field does not depend on the distance from the plate. Therefore, the strenght of the electric field at 4 cm from the plate is equal to the strength of the electric field at 2 cm from the plate:
Answer:
D. must have a moon
Explanation:
Scientists say that a planet must orbit a star, must be round, and must be big enough so its gravity clears its orbit of other objects. Therefore, the statement that is not a requirement for a planet is
D. must have a moon
For example, Mercury and Venus are planets with no moons.
Answer:
3.33 Joules Per Second
Explanation:
Before finding the Power, we need to calculate the Work Done. The Work Done can be calculated using the formula:
WD = F × d
where F is the Magnitude of Force in <em>N</em>
<em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em><em> </em>d is the Parallel Distance moved by the object in <em>m</em><em>.</em>
Hence, by Applying this formula, we get:
WD = (5)(20)
= 100 J
From here calculating Power is simple as it is the Rate of Work Done. Hence,
Power = 100/30
= <u>3</u><u>.</u><u>3</u><u>3</u><u> </u><u>J</u><u>/</u><u>s</u>
Therefore, the power put out is <u>3</u><u>.</u><u>3</u><u>3</u><u> </u><u>J</u><u>o</u><u>u</u><u>l</u><u>e</u><u>s</u><u> </u><u>p</u><u>e</u><u>r</u><u> </u><u>S</u><u>e</u><u>c</u><u>o</u><u>n</u><u>d</u><u>.</u>
Apparent diameter is the answer