Answer:
the fraction of submerged volume is equal to the ratio of the densities of the body between the density of the fluid.
Explanation:
This is a fluid mechanics problem, where as the boat is in equilibrium with the pushing force we can write Newton's second law
B- W = 0
B = W
the thrust force is equal to the weight of the liquid that is dislodged
B = ρ g V
we substitute
ρ g V = m g
V = m /ρ_fluid 1
we can write the mass of the pot as a function of its density
ρ_body = m / V_body
m = ρ_body V_body
V_fluid / V_body = ρ_body / ρ _fluid 2
Equations 1 and 2 are similar, although 2 is easier to analyze, the fraction of submerged volume is equal to the ratio of the densities of the body between the density of the fluid.
The effect appears the pot as if it had a lower apparent weight
The first: alright, first: you draw the person in the elevator, then draw a red arrow, pointing downwards, beginning from his center of mass. This arrow is representing the gravitational force, Fg.
You can always calculate this right away, if you know his mass, by multiplying his weight in kg by the gravitational constant

let's do it for this case:

the unit of your fg will be in Newton [N]
so, first step solved, Fg is 637.65N
Fg is a field force by the way, and at the same time, the elevator is pushing up on him with 637.65N, so you draw another arrow pointing upwards, ending at the tip of the downwards arrow.
now let's calculate the force of the elevator

so you draw another arrow which is pointing downwards on him, because the elevator is accelating him upwards, making him heavier
the elevator force in this case is a contact force, because it only comes to existence while the two are touching, while Fg is the same everywhere
Nitrogen, oxygen, and argon
Explanation:
A charge alters the space around it. This alteration of space is called the electric field. It is also defined as the electric force acting on a charged particle per unit test charge. It is given by :

Where
F is the electric force, 
The direction of electric field is in the direction of electric force. For a positive charge, the direction of electric field lines are outwards and for a negative charge, the direction of field lines are inwards.
Hence, the correct option is (c) "electric field".