Answer:
There are 756.25 electrons present on each sphere.
Explanation:
Given that,
The force of repression between electrons, 
Let the distance between charges, d = 0.2 m
The electric force of repulsion between the electrons is given by :




Let n are the number of excess electrons present on each sphere. It can be calculated using quantization of charges. It is given by :
q = ne


n = 756.25 electrons
So, there are 756.25 electrons present on each sphere. Hence, this is the required solution.
Answer:
Time zone is one important factor in difference in location and this in turn affects the result of the resolution and rotation of shadow produced from the sun or other illumination.
Therefore someone at a place might see a clear large shadow due to shinny sun reflection and another a small or dull Shadow at same time if the intensity of the sun or lighting source is going down.
Explanation:
The closer a body/object is to a lighting source the larger the shadow it produces, and the farther the body the smaller the shadow produced.
Answer:
Yes
Explanation:
Since velocity is a vector, meaning it also relies on direction, the average speed can be different from her average velocity. An example would be if a runner turned around and ran backward after running 10 meters and returned to her starting point. If you took her average velocity of the entire trip it would actually be 0 but her average speed obviously would not be. This is why velocity can be negative but speed cannot.
Answer:
Initial velocity is 0 .. ( since it is just dropped)
now using V²= u² +2gh
=> (Vfinal)² = 0+2*10*20
=> v² = 20*20 = 400
=> v = √400 = 20m/s
for time taken
use V = u+gt
=> t = V/g = 20/10 = 2sec