Two cars P and Q are moving on a road in the same direction. Accleration of car P increases linearly with time whereas car Q moves with a constant…

Two cars P and Q are moving on a road in the same direction. Accleration of car P increases linearly with time whereas car Q moves with a constant accleration. Both cars cross each other at time $\displaystyle \mathrm{t}=0$, for the first time. The maximum possible number of crossing(s) (including the crossing at $\displaystyle \mathrm{t}=0$ ) is $\displaystyle \_\_\_\_$.