This may helpv^2=u^2+2as. v=0 at top of flight. a=acceleration of gravity(vo^2)/2a=s.
The headlamp's concave mirror is open on one end, and the light bulb's filament is placed at or near the focus. (Sorry if this is Wrong)
Transferring your estate in the manner you have specified
Inertia is the correct answer!
