Draw graphs $a \to t$,$v \to t$,and $x \to t$ for an object falling freely.

(N/A) For an object falling freely,the acceleration is constant and equal to $-g$. Thus,graph $(a)$ shows the constant acceleration with respect to time $(a \to t)$.
The velocity of an object falling freely is given by $v = -gt$. This represents a linear relationship with time,as shown in graph $(b)$ for $v \to t$.
The displacement of an object falling freely is given by $x = -\frac{1}{2}gt^2$ (taking downward as negative). This represents a parabolic relationship with time,as shown in graph $(c)$ for $x \to t$.