A particle executes SHM with a period of 8 s. Half a second after it crosses the equilibrium position, it is at a point P. The minimum time interval after which it will be again at P is                                          

The time taken to move from equilibrium position to extreme position is T/4 = 2 s. As it takes 1/2   s to reach P, to move from P to extreme position it takes 1.5 s and for return journey another 1.5 s. Hence after 3 s it will be again at P