There are two vertical walls separated by a distance `3 m`. A projectile is projected from the foot of one wall with a speed `10 sqrt(2) m / s` at angle `45^(circ)` with horizontal as shown in the figure. During its motion, it collides many a times with vertical walls elastically. During collision, the velocity of the 'projectile perpendicular to wall get reversed and the one which is parallel to wall remains unchanged. The number of collision projectile will make with the vertical walls before hitting the ground is
'(##CEN_KSR_PHY_JEE_C08_E01_021_Q14##)'

Answer

6