Answer:
at r < R;
at 2R > r > R;
at r >= 2R
Explanation:
Since we have a spherically symmetric system of charged bodies, the best approach is to use Guass' Theorem which is given by,
(integral over a closed surface)
where,
= Electric field
= charged enclosed within the closed surface
= permittivity of free space
Now, looking at the system we can say that a sphere(concentric with the conducting and non-conducting spheres) would be the best choice of a Gaussian surface. Let the radius of the sphere be r .
at r < R,
= 0 and hence = 0 (since the sphere is conducting, all the charges get repelled towards the surface)
at 2R > r > R,
= Q,
therefore,
(Since the system is spherically symmetric, E is constant at any given r and so we have taken it out of the integral. Also, the surface integral of a sphere gives us the area of a sphere which is equal to 
)
or,
at r >= 2R
= 2Q
Hence, by similar calculations, we get,
Push is in, pull is out
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Contact Forces
Frictional Force
Tension Force
Normal Force
Air Resistance Force
Applied Force
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Action-at-a-Distance Forces
Gravitational Force
Electrical Force
Magnetic forces
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Very bottom, last part
First drawing: Arrow down above box
Second drawing: Arrow up from below box
Answer:
By making the object sharp pointed
Answer:
Energy absorbed or hidden when water evaporates
Explanation:
The heat that is required to make a phase change is known as latent heat.
A phase change occurs when matter changes state. For example from solid to liquid, from liquid to gas, among others.
When changing from liquid to gas (for example when water evaporates), the heat necessary for this to happen is called latent heat of vaporization. The word latent means hidden, because a change in temperature is not perceived during the phase change, even when heat is being added, thus it is said that the heat is hidden or latent.
So the answer is:
- Energy absorbed or hidden when water evaporates.
*Another type of latent heat is the latent heat of fusion, which is when a solid becomes liquid.
