Two projectiles collide in air, then for just after and before the collision

Two projectiles are projected simultaneously from two towers as shwon in figure. If the projectiles collide in the air, then find the distance "s" between the towers.

If a projectile explods in mid air then just before and just after explosion, choose correct option(s)

Two smooth balls A and B , each of mass m and radius R , have their centres as shown in fig. Ball A , moving along positive x-axis, collides with ball B . Just before the collision, speed of ball 'A' is 4m//s and ball 'B' is stantionary. The collision Velocity of the ball 'A' just after the collision is

Two smooth balls A and B , each of mass m and radius R , have their centres as shown in fig. Ball A , moving along positive x-axis, collides with ball B . Just before the collision, speed of ball 'A' is 4m//s and ball 'B' is stantionary. The collision What is velocity of ball 'B' after collision is

Two particles are seen to collide and move jointly together after the collision . During such a collision, for the total system,

Two particles are seen to collide and move jointly together after the collision . During such a collision, for the total system,

Two identical balls A and B collide head on elastically. If velocities of A and B, before the collision are +0.5 m/s and -0.3 m/s respectively, then their velocities, after the collision, are respectively