Answer:
c) 
Explanation:
Coulomb's law says that the force exerted between two charges is inversely proportional to the square of distance between them, and is given by the expression:

where k is a proportionality constant with the value 
In this case
, so we have:

Solving the equation for q, we have:



Replacing the given values:


Atoms of the same element having equal numbers of protons, but different numbers of neutrons is called isotope.
Answer:
-0.0047 rad/s²
335.103 seconds
99.18 seconds
Explanation:
= Final angular velocity
= Initial angular velocity = 1.5 ra/s
= Angular acceleration
= Angle of rotation = 40 rev
t = Time taken
Equation of rotational motion

Acceleration while slowing down is -0.0047 rad/s²

Time taken to slow down is 335.103 seconds

Solving the equation

The time required for it to complete the first 20 is 99.18 seconds as 539.11>335.103
Yes, even light rays can vary in wavelength and frequency, if the length of the ray is sorter, it becomes more energetic and has a higher frequency. If you're talking about a ray tracing diagram for lenses or mirrors, the length of the ray doesn't really matter unless you're finding the path length but there are some procedures for that too. Let me know if I missed what you were asking.
Answer:
A. Using
Pgauge= Pmanometer
And we know that
Pgauge= deta(hpg)
So deta h = Pgauge/density x g
So
= 7.5(6894.76/1psig)/ 13.6*10^3*9.8m/s²)
= 387.9mm
So to find height of pipe connected to the pipe we say
= h -deta h
= 900-387.97mm
=512.02mm
B. We use manometry principle
Pgas+density xg(25*10^3)-PX density{h-(H-0.25)=0
So
Finally Pgas= 6.54psig