Answer:
The correct answer is B
Explanation:
Let's calculate the electric field using Gauss's law, which states that the electric field flow is equal to the charge faced by the dielectric permittivity
Φ
= ∫ E. dA =
/ ε₀
For this case we create a Gaussian surface that is a sphere. We can see that the two of the sphere and the field lines from the spherical shell grant in the direction whereby the scalar product is reduced to the ordinary product
∫ E dA =
/ ε₀
The area of a sphere is
A = 4π r²
E 4π r² =
/ ε₀
E = (1 /4πε₀
) q / r²
Having the solution of the problem let's analyze the points:
A ) r = 3R / 4 = 0.75 R.
In this case there is no charge inside the Gaussian surface therefore the electric field is zero
E = 0
B) r = 5R / 4 = 1.25R
In this case the entire charge is inside the Gaussian surface, the field is
E = (1 /4πε₀
) Q / (1.25R)²
E = (1 /4πε₀
) Q / R2 1 / 1.56²
E₀ = (1 /4π ε₀
) Q / R²
= Eo /1.56
²
= 0.41 Eo
C) r = 2R
All charge inside is inside the Gaussian surface
=(1 /4π ε₀
) Q 1/(2R)²
= (1 /4π ε₀
) q/R² 1/4
= Eo 1/4
= 0.25 Eo
D) False the field changes with distance
The correct answer is B
The velocity of the ball when it was caught is 12.52 m/s.
<em>"Your question is not complete it seems to be missing the following, information"</em>,
find the velocity of the ball when it was caught.
The given parameters;
maximum height above the ground reached by the ball, H = 38 m
height above the ground where the ball was caught, h = 30 m
The height traveled by the ball when it was caught is calculated as follows;
y = H - h
y = 38 - 30 = 8 m
The velocity of the ball when it was caught is calculated as;

Thus, the velocity of the ball when it was caught is 12.52 m/s.
Learn more here: brainly.com/question/14582703
Answer:
your answer is B. The velocity could be in any direction, but the acceleration is in the direction of the resultant force
<span>work =V*Q
=12*50*10^-6
The total work done will be equal to
work = V.Q
which means
w= 12 . 50.10^-6
Hence,
w= 0.0006 J</span>