1. A skydiver jumps from a moving aircraft at an altitude of 10 000 feet directly above a fixed point, O, on the ground.  The trajectory of the skydiver is then modelled by the function

$h(x)=3048-0.5{x}^{2}$

where $h$ m is the height of the skydiver above the ground and $x$m is the horizontal distance along the ground from point O.

(i) Explain why the value 10 000 does not appear in the model.

(ii) Find the height of the skydiver at the point when they have covered a ground distance of $60m$.

(iii) How much ground has the skydiver covered when they land on the ground?