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)
Winds that blow from the north and south poles would be called k<span>atabatic winds. I'm not sure if I spelled that right, but that's the answer I hope.</span>
It would <span>keep rolling without slowing down if no friction acted upon it.
</span>