Step-by-step explanation:
Lets take gravitational force(F) and mass(m) and distance (r)
now for a body in contact with the surface of the earth, its mass is also considered(m‘),now the mass of the earth(m") is also considered,then the distance from the body to the center of the earth (r).ie it r because its practically the radius of the earth. is also considered
So by using dimensional analysis ....
we get F a m'•m"/r² ,where a is proportional to.
now since F is directly increaseproportional to m ie. F a m, then an increase in mass of the body increases it's gravitational force(and clearly that makes sense because the bigger you are the stronger you get pulled to the ground)
then we also see that F is inversely proportional to r ie.F a 1/r ,then an increase in the distance between the ground an the object decrease it's gravitational force ( meaning as any object on earth keeps on moving away from the ground the gravitational force between the object and the center of the earth is weak, when it reaches space then the force becomes virtually negligible!)
So to answer the second question, we clearly see that doubling the mass of the body increases the gravitational force between it and the earth
and doubling the distance on the other hand will decrease the attraction between the body and the earth
So a body forcefully projected into the air fights against gravity but its easier as it keeps on getting higher, If it has a greater mass like that of a trail or truck , it will not even probably stay in the air for long , unless its projected with a very high velocity
I hope this helps, and you can ask me any question concerning this via the comments platform.