Which has a greater effect on potential energy: mass or height?

Neither does. Their effects are EQUAL.

Potential energy = (MASS) x (gravity) x (HEIGHT)

You should be able to look at this formula and see that the effects of mass and height are equal.  Gravitational potential energy is directly proportional to both of them.

If you want to increase the potential energy of some object, say, by 42%, you can do it either way ... either increase the object's mass by 42%, OR raise the object 42% higher than it is now.  Either of those changes will have the same effect on the object's potential energy.

the answer is a 3.8cm

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.