Your friend phred says ""i decided to make one of those online personality tests as a project in my psychology class. how hard c
1 answer:
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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
Answer:
The equation of motion is
Explanation:
Lets calculate
The weight attached to the spring is 24 pounds
Acceleration due to gravity is
Assume x , is spring stretched length is ,4 inches
Converting the length inches into feet
The weight (W=mg) is balanced by restoring force ks at equilibrium position
mg=kx
⇒
The spring constant ,
= 72
If the mass is displaced from its equilibrium position by an amount x, then the differential equation is
Auxiliary equation is,
=
Thus , the solution is
The mass is released from the rest x'(0) = 0
=0
Therefore ,
Since , the mass is released from the rest from 4 inches
inches
feet
feet
Therefore , the equation of motion is