Both stones move relative to the earth with the same constant and uniform acceleration g. Clearly one stone moves uniformly in relation to the other, and the constant speed of the first stone in relation to the other is equal to that speed which the first stone acquires in 1 sec, i.e. in the period that elapses between the two moments at which the stones start falling.
It is not difficult to carry out the necessary calculation.
The distance travelled by the first stone is found from the equation
s1=2gt2
The distance travelled by the second stone from the equation
s2=2g(t−1)2
The distance between the two stones increases with the lapse of time according to the formula
s1−s2=gt−2g,
i.e. the first stone moves uniformly in relation to the second stone with a velocity numerically equal to g.
88' SOLUTIONS