Answer:
D
Explanation:
Energy is never created nor destroyed.
Answer:
a) 8.99*10³ V b) 4.5*10⁻² J c) 0 d) 0
Explanation:
a)
- The electrostatic potential V, is the work done per unit charge, by the electrostatic force, producing a displacement d from infinity (assumed to be the reference zero level).
- For a point charge, it can be expressed as follows:

- As the electrostatic force is linear with the charge (it is raised to first power), we can apply superposition principle.
- This means that the total potential at a given point, is just the sum of the individual potentials due to the different charges, as if the others were not there.
- In our case, due to symmetry, the potential, at any corner of the triangle, is just the double of the potential due to the charge located at any other corner, as follows:

- The potential at point C is 8.99*10³ V
b)
- The work required to bring a positive charge of 5μC from infinity to the point C, is just the product of the potential at this point times the charge, as follows:

- The work needed is 0.045 J.
c)
- If we replace one of the charges creating the potential at the point C, by one of the same magnitude, but opposite sign, we will have the following equation:

- This means that the potential due to both charges is 0, at point C.
d)
- If the potential at point C is 0, assuming that at infinity V=0 also, we conclude that there is no work required to bring the charge of 5μC from infinity to the point C, as no potential difference exists between both points.
Answer:

Explanation:
The radius of Earth is 
The density of an object is given by :

The density of Erth is, d = 5515 kg/m³
Where
m is the mass of the Earth
So,

Put all the values,

So, the mass of the Earth is equal to
.
Answer:
a
The total distance traveled is 
b
The average velocity is 
Explanation:
From the question we are told that
The time taken for first part 
The speed for the first part is 
The time taken for second part is 
The speed for the second part is 
The time taken for third part is
The speed for the third part is 
Generally

Therefore the total distance traveled is

substituting values


Generally the average velocity is mathematically represented as

Where
is the total time taken which is mathematically represented as


The average velocity is


Answer:
moving
Explanation:
They've been moving for thousands and thousands of years. Millions of years ago there was a land called Pangea that seperated into the continents we see today.