Two particles ${\mathrm{P}}_1$ and ${\mathrm{P}}_2$ are performing SHM along the same line about the same mean position. Initially, they are at their positive extreme position. If the time period of each particle is 12 s and the difference of their amplitudes is 12 cm then find the minimum time (in seconds) after which the separation between the particles become 6 cm.

Hence, the correct answer is 2.