Answer:
Explained
Explanation:
i)Two spheres hanging from nylon threads attract each other because either the two spheres are charged with opposite sign or only one of the spheres is charge so the other would be charge by induction of the charged sphere and hence attract each other.
ii)However, when they are touched the charges will be rearranged among the two sphere such that the two sphere have exact same magnitude and sign of charge and now they will repel each other or the magnitude of charges on the two spheres become zero and they neither attract or repel each other.
Answer:
A). σ = 3.823 x 
/N-
B). 
C/
C). 
J
Explanation:
A). We know magnitude of charge per unit area for a conducting plate is given by
where, E is resultant electric field = 1.2 x 
V/m
is permittivity of free space = 8.85 x 
/N-
k is dielectric constant = 3.6
∴
= 3.6 x 8.85 x x 1.2 x
= 3.823 x /N-
B).Now we know that the magnitude of charge per unit area on the surface of the dielectric plate is given by
C/
C).
Area of the plate, A = 2.5 
= 2.5 x 
diameter of the plate, d = 1.8 mm
= 1800 m
∴ Total energy stored in the capacitor
J
Kinetic energy is calculated through the equation,
KE = 0.5mv²
At initial conditions,
m₁: KE = 0.5(0.28 kg)(0.75 m/s)² = 0.07875 J
m₂ : KE = 0.5(0.45 kg)(0 m/s)² = 0 J
Due to the momentum balance,
m₁v₁ + m₂v₂ = (m₁ + m₂)(V)
Substituting the known values,
(0.29 kg)(0.75 m/s) + (0.43 kg)(0 m/s) = (0.28 kg + 0.43 kg)(V)
V = 0.2977 m/s
The kinetic energy is,
KE = (0.5)(0.28 kg + 0.43 kg)(0.2977 m/s)²
KE = 0.03146 J
The difference between the kinetic energies is 0.0473 J.
The correct option is D.
The model developed by Ptolemy has a lot of inconsistency and during the middle age additional explanation was offered for the claims made by the model. The model was very complicated because it was based on erroneous assumptions.
Copernicus model was simpler and some of his claims were correct.<span />
