Which of the following statements are true? a) the resistance of a conductor is proportional to the conductivity of the material of which the conductor is composed. b) the resistance of a conductor is proportional to the resistivity of the material of which the conductor is composed. c) a material that obeys ohm's law reasonably well is called an ohmic conductor or a linear conductor. d) good conductors of electricity have larger conductivity values than insulators. e) semiconductors have resistivity values that are larger than those of insulators.

The following statements are true

B) The resistance of a conductor is proportional to the resistivity of the material of which the conductor is composed.

C) A material that obeys Ohm's law reasonably well is called an ohmic conductor or a linear conductor.

D) Good conductors of electricity have larger conductivity values than insulators.

Explanation:

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.