It might be to late but the answer is C
Answer:
1.424 μC
Explanation:
I'm assuming here, that the charged ball is suspended by the string. If the string also is deflected by the angle α, then the forces acting on it would be: mg (acting downwards),
tension T (acting along the string - to the pivot point), and
F (electric force – acting along the line connecting the charges).
We then have something like this
x: T•sin α = F,
y: T•cosα = mg.
Dividing the first one by the second one we have
T•sin α/ T•cosα = F/mg, ultimately,
tan α = F/mg.
Since we already know that
q1=q2=q, and
r=2•L•sinα,
k=9•10^9 N•m²/C²
Remember,
F =k•q1•q2/r², if we substitute for r, we have
F = k•q²/(2•L•sinα)².
tan α = F/mg =
= k•q²/(2•L•sinα)² •mg.
q = (2•L•sinα) • √(m•g•tanα/k)=
=(2•0.5•0.486) • √(0.0142•9.8•0.557/9•10^9) =
q = 0.486 • √(8.61•10^-12)
q = 0.486 • 2.93•10^-6
q = 1.424•10^-6 C
q = 1.424 μC.
Answer:
The top of the ladder go down by 0.15 m.
Explanation:
Here we have right angled triangle.
Hypotenuse = 4.6 m
Bottom angle = 66º
Length from ladder bottom to wall bottom = 4.6 cos66 = 1.87 m
Length from ladder top to wall bottom = 4.6 sin66 = 4.20 m
New length from ladder bottom to wall bottom = 1.87 + 0.31 = 2.18 m
By Pythagoras theorem
New length from ladder top to wall bottom is given by
Distance the top of the ladder go down = 4.20 - 4.05 = 0.15 m
An incandescent bulb produces light that comes from the heating of a filament. A compact fluorescent bulb produces light when a substance is hit by electromagnetic radiation. Compact fluorescent bulbs are more efficient than incandescent bulbs.
The first law of thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic processes. Therefore, a system with lower heat emissions would be more efficient.
The second law of thermodynamics states that the total entropy of an isolated system (the thermal energy per unit temperature that is unavailable for doing useful work) can never decrease. In our context, it means that the system with the least amount of losses would be more efficient. As a conclusion the fluorescent bulb would be more efficient.
The answer is reveal urges and desires mask by the unconscious mind. According to Freud, Dreams reveal urges and desires mask by the unconscious mind. In terms of the unconscious. The purpose of dreams, as stated by Freud, is to fulfill repressed wishes through the process of dreaming, since they cannot be fulfilled in real life. .In our dreams, we can understand what it is what we want and desire, things that we might not be able to admit to ourselves while we are awake. Dreams also reveal our unconscious mind, the things we might want or need, but do not even realize ourselves.