Answer:
(A) 421 J energy stored in the capacitor for one flash.
(B) The value of capacitance is 0.0537 F
Explanation:
Given :
(A)
Time 
Average power
W
From power equation,

So energy in one light is given by,

J
Since efficiency is 95 % so we can write, energy stored in one flash,
J
(B)
From the formula of energy stored in capacitor,

Where
and
V



Answer: a) the force will be repulsive
b) the ratio of the new force to the old force will be 2
c) O
Explanation:
a) since charge -Q is moved from A to B, this implies that sphere A is negatively charged. The two spheres are now negatively charged and will repel themselves.
b) initial force will be -q(-Q)/d2
Adding extra charge -Q will cause change on B to become -2Q
The new force will be - 2Q(-q)/d2
Dividing new force by old force will give 2
C) if B is neutralized, the net charge becomes 0 and there will be no force on it.
Answer:
"The distance between crests is 3 cm."
Explanation:
If he writes down "The distance between crests is 3 cm."
That means he is describing the wavelength of a wave and not longitudinal wave. He ought to write something about " direction "
Longitudinal waves are waves in which the displacement of the medium is in the same direction as, or parallel to, the direction of propagation of the wave. While
Wavelength is the distance between the two successfully Crest or trough
Answer:
a) force between them is attraction, b) F = 1.125 10⁻² N
Explanation:
In this case the electric force is given by Coulomb's law
F =
In the exercise they give us the values of the loads
q1 = - 10 mC = -10 10⁻³ C
q2 = 5 mC = 5 10⁻³ C
d = 20 cm = 0.20 m
let's calculate
F = 9 10⁹
F = 1.125 10⁻² N
To find the direction of the force we use that charges of the same sign repel each other, as in this case there is a positive and a negative charge, the force between them is attraction
The speed would be in a decimal? Or do you want it in a fraction?