Angle of inclination on the plane is Ө=45˚,

The body falls through the height h = 5 m,

Acceleration due to gravity g = 10 m/s,

The striking velocity of the projectile with the inclined plane is

After collision, let it make an angle θ with horizontal. The horizontal component of velocity 10 cos45°= v cos Ө˚ will remain unchanged and the velocity in the perpendicular direction to the plane after collision will be

So,

Angle of reflection from the wall

Angle of projection will be

Let the distance where it falls is l

From equation of trajectory

Putting values, we get

On solving above, we get

Thus, it will hit the plane again at 18.5 m along the incline.