Answer:
State A = piece of metal; State B = air
Explanation:
For the three main states of matter here's how it breaks down.
Solid - Cannot be compressed and retains its shape
Liquid - Cannot be compressed and does not retain its shape
Gas - Compressible and does not retain its shape.
Knowing this State A has to be solid. Only one of the options has A as a solid, so that's the answer. Worth knowing state B is a gas though, only one compressible, just like solid is the only one that retains its shape.
0J
According to the law of conservation of energy, the potential energy is converted to kinetic energy. Remember, potential energy is calculated using height and weight. If the ball is on the ground, height is 0.
Complete Question
The complete question is shown on the first uploaded image (reference for Photobucket )
Answer:
The electric field is 
Explanation:
From the question we are told that
The linear charge density on the inner conductor is 
The linear charge density on the outer conductor is

The position of interest is r = 37.3 mm =0.0373 m
Now this position we are considering is within the outer conductor so the electric field at this point is due to the inner conductor (This is because the charges on the conductor a taken to be on the surface of the conductor according to Gauss Law )
Generally according to Gauss Law

=> 
substituting values


The negative sign tell us that the direction of the electric field is radially inwards
=> 
I haven´t learned that yet I´m sorry.