Answer:
A., B., and C.
Explanation:
An Ohmic material is a material that obeys Ohm's Law, V = IR.
In contrast, a non-Ohmic material is one that does not obey Ohm's law.
Ohm's law states that the voltage across an electrical object is proportional to the current flowing through it, with the constant of proportionality being Resistance, R (in Ohm's).
The only Non-Ohmic material is the semiconductor, as semiconductors do not obey Ohm's law.
Answer:
The mass of the cargo is 
Explanation:
From the question we are told that
The radius of the spherical balloon is 
The mass of the balloon is
The volume of the spherical balloon is mathematically represented as

substituting values


The total mass the balloon can lift is mathematically represented as

where
is the density of helium with a value of

and
is the density of air with a value of

substituting values


Now the mass of the cargo is mathematically evaluated as


I cant read it, i could most likely help if i could read it.
You can use the displacement method or the eureka can so basically in the displacement can what you have to do is to put some water into a measuring cylinder and measure its volume before adding the irregular shaped object and then measuring the level of water which had been displaced and then eureka can you can check online