A projectile is launched from point A and with a speed u making an angle of theta with the horizontal. It collides at point B and bounces back into the air and collides a second time at point C. What is the length of BC and the time interval between the collisions at B and C? Using this solution, derive general expressions for (a) the horizontal range of the projectile between nth and n+1th collision and (b) the time interval between the nth and n+1th collision.