Answer:
Following are the answer to this question:
Explanation:
Formula:

Calculating point A:
when the value is 




Calculating point B:
when the value is 



Calculating point C:
when the value is 




Calculating point D:
when the value is 




Calculating point E:
when the value is 




Answer: Positive
Explanation:
Are you familiar with differential calculus? In a plot of position vs. time, the velocity at any given moment is the derivative at that point. A derivative is just the slope. For this plot, the slope is x/t.
Looking at t = 1s, the slope is 1/1. This means the velocity is a positive 1m/s at time equal to 1 second
The question is missing, however, I guess the problem is asking for the value of the force acting between the two balls.
The Coulomb force between the two balls is:

where

is the Coulomb's constant,

is the intensity of the two charges, and

is the distance between them.
Substituting these numbers into the equation, we get

The force is repulsive, because the charges have same sign and so they repel each other.
in case you dont want to read the answer is B
Answer:
This represents radiation in ultra-violet region .
Explanation:
Energy of the orbit where n = 3 is given as follows

= -1.511 eV
Energy of the orbit where n = 1 is given as follows

= 13.6 eV
Difference of [tex]E_3 and [tex]E_1 = - 1.511+ 13.6
= 12.089 eV.
The wavelength of light having this energy in nm is given by the expression as follows
Wavelength in nm = 1244 / energy in eV
= 1244 / 12.089
= 102.90 nm
This represents radiation in ultra-violet region .