Projectile questions require resolving velocities and acceleration into components so make sure you're solid at that.
in this question you've got an object with a constant horizontal component of velocity of 0.52 m/s and it is in motion for 0.9 seconds... you're asked to find is it's final horizontal displacement?
i.e. how far does something travel if it moves for 0.9 seconds at a constant velocity of 0.52 m/s