Answer:
a) E = ρ / e0
b) E = ρ*a / (e0 * r)
c) E = 0
Explanation:
Because of the geometry, the electric field lines will all have a radial direction.
Using Gauss law

Using a Gaussian surface that is cylinder concentric to the cable, the side walls will have a flux of zero, because the electric field lines will be perpendicular. The round wall of the cylinder will have the electric field lines normal to it.
We can make this cylinder of different radii to evaluate the electric field at different points.
Then:
A = 2*π*r (area of cylinder per unit of length)
Q/e0 = 2*π*r*E
E = Q / (2*π*e0*r)
Where Q is the charge contained inside the cylinder.
Inside the cable core:
There is a uniform charge density ρ
Q(r) = ρ * 2*π*r
Then
E = ρ * 2*π*r / (2*π*e0*r)
E = ρ / e0 (electric field is constant inside the charged cylinder.
Between ther inner cilinder and the tube:
Q = ρ * 2*π*a
E = ρ * 2*π*a / (2*π*e0*r)
E = ρ*a / (e0 * r)
Outside the tube, the charges of the core cancel each other.
E=0
Answer:
Change in potential energy of the block-spring-Earth
system between Figure 1 and Figure 2 = 1 Nm.
Explanation:
Here, spring constant, k = 50 N/m.
given block comes down eventually 0.2 m below.
here, g = 10 m/s.
let block be at a height h above the ground in figure 1.
⇒In figure 2,
potential energy of the block-spring-Earth
system = m×g×(h - 0.2) + 1/2× k × x². where, x = change in spring length.
⇒ Change in potential energy of the block-spring-Earth
system between Figure 1 and Figure 2 = (m×g×(h - 0.2)) - (1/2× k × x²)
= (1×10×0.2) - (1/2×50×0.2×0.2) = 1 Nm.
Answer:
D: The distance between the particles decreases
Explanation:
Taking away energy slows down molecules, like how you slow down when you are cold (I think)
Answer:How is potential energy converted to thermal energy in a system?
Explanation:
Answer:
3.12 x 10^-5 m
Explanation:
Length of steel column, L = 4 m
diameter, d = 0.2 m
radius = half of diameter = 0.1 m
Young's modulus, Y = 2 x 10^11 N/m^2
Mass of truck, m = 5000 kg
Force, F = mass of truck x acceleration due to gravity
F = 5000 x 9.8 = 49000 N
Area of crossection of cable,
A = 
Let ΔL be the shrink in length of cable, then by the formula of Young's modulus



ΔL = 3.12 x 10^-5 m
Thus, the shrink in the length of cable is 3.12 x 10^-5 m.