# Thread: Calculate the velocity of the brick using an assumption & draw the displacement-time graph

Originally Posted by MarkFL
Why do you have the brick returning to zero displacement?
Then is the graph without returning to zero displacement

2. Originally Posted by mathlearn
Then is the graph without returning to zero displacement
For the record, you're assuming that the brick ends up in sand at the bottom of the slope, coming to an abrupt stand still.
The corresponding graphs then look like:
\begin{tikzpicture}[font=\LARGE]
\draw[thick, gray, ->] (0,0) -- (9,0) node[right] {$t$};
\draw[thick, gray, ->] (0,-6) -- (0,4.5);
\draw[ultra thick, red] (0,2) node[left] {$a$} -- (5,2) -- (5,-6) -- (6,-6) -- (6,0) -- (8,0);
\draw[ultra thick, blue] (0,0) -- (5,4) -- (6,0) -- (8,0) node[above] {$v$};
\draw[ultra thick, olive] (0,0) parabola (5,3) parabola bend (6,3.6) (6,3.6) -- (8,3.6) node[right] {$d$};
\end{tikzpicture}
(Just had to make the TikZ drawing. )