Answer:
E = 2k 
Explanation:
Gauss's law states that the electric flux equals the wax charge between the dielectric permeability.
We must define a Gaussian surface that takes advantage of the symmetry of the problem, let's use a cylinder with the faces perpendicular to the line of charge. Therefore the angle between the cylinder side area has the same direction of the electric field which is radial.
Ф = ∫ E . dA = E ∫ dA = q_{int} /ε₀
tells us that the linear charge density is
λ = q_ {int} /l
q_ {int} = l λ
we substitute
E A = l λ /ε₀
is area of cylinder is
A = 2π r l
we substitute
E = 
E = 
the amount
k = 1 / 4πε₀
E = 2k
I believe the answer is Microwaves (just to clarify, not the oven). They're widely used for communications.<span />
Answer:
A) 138.8g
B)73.97 cm/s
Explanation:
K = 15.5 Kn/m
A = 7 cm
N = 37 oscillations
tn = 20 seconds
A) In harmonic motion, we know that;
ω² = k/m and m = k/ω²
Also, angular frequency (ω) = 2π/T
Now, T is the time it takes to complete one oscillation.
So from the question, we can calculate T as;
T = 22/37.
Thus ;
ω = 2π/(22/37) = 10.5672
So,mass of ball (m) = k/ω² = 15.5/10.5672² = 0.1388kg or 138.8g
B) In simple harmonic motion, velocity is given as;
v(t) = vmax Sin (ωt + Φ)
It is from the derivative of;
v(t) = -Aω Sin (ωt + Φ)
So comparing the two equations of v(t), we can see that ;
vmax = Aω
Vmax = 7 x 10.5672 = 73.97 cm/s
Option A is correct answer
Given:
Horizontal distance between two boats = x = 14 m
One boat is at trough, the other is at crest.
As there is no crests between them meaning the boat are next to each other.
Wavelength is the distance between two consecutive crests/troughs = w
The distance between a crest and a trough next to it = w/2
Complete cycles = c = 5
Time taken for c cycles = t = 15 s
Vertical distance between two boats = y = 2.4 m
To find:
wavelength = w = 2x = 28 m
Amplitude = A = Displacement from mean to extreme position = y/2 = 1.2 m
Time period for one cycle = T = t/c = 15/5 = 3 s/cycle
frequency = 1/T = 1/3 = 0.33 hertz
speed = wavelength/Period = w/T = 28/3 = 9.33 m/s
