Answer:
The permittivity of rubber is 
Explanation:
From the question we are told that
The magnitude of the point charge is 
The diameter of the rubber shell is 
The Electric field inside the rubber shell is 
The radius of the rubber is mathematically evaluated as

Generally the electric field for a point is in an insulator(rubber) is mathematically represented as
Where
is the permittivity of rubber
=> 
=> 
substituting values


Answer:
The beam of light is moving at the peed of:
km/min
Given:
Distance from the isalnd, d = 3 km
No. of revolutions per minute, n = 4
Solution:
Angular velocity,
(1)
Now, in the right angle in the given fig.:

Now, differentiating both the sides w.r.t t:

Applying chain rule:


Now, using
and y = 1 in the above eqn, we get:

Also, using eqn (1),


The radiation is ultra voilet or Gamma radiation , because their wave length is very short i e 1..0 to 2.5 (angstrom)Ao.
Answer:
It remains constant
Explanation:
As we know that buoyant force on an object given as
Fb = ρ Vd g
ρ= Density of fluid
Vd=Volume displace by body
g=10 m/s²
Fb =buoyant force
So from above we can say that buoyant force does not depends on the depth. It only depends on the fluid density and volume displace by body.
So when rock gets deeper and deeper the buoyant force will remain constant.
It remains constant