Final answer:
The correct process for adjusting sights for accurate shooting is sighting-in, which accounts for gravity's effect over a specific range. A higher muzzle velocity decreases bullet drop by reducing gravity's time to act, but increased air resistance can offset some benefits.
Step-by-step explanation:
The process that will help adjust your sights to hit the bull's-eye consistently is D) Sighting-in. This process involves adjusting the gun sights to aim higher to compensate for the effect of gravity. As a result, the gun is made accurate only for a specific range.
(a) If a gun is sighted to hit targets at the same height as the gun and 100.0 m away, and the muzzle velocity of the bullet is 275 m/s, the bullet will hit lower when aimed directly at a target 150.0 m away due to gravity affecting the bullet over a longer distance.
(b) A larger muzzle velocity would result in the bullet traveling faster, which generally decreases the time gravity has to act on it, thus reducing the bullet drop at the same distance. However, air resistance would increase with speed, potentially offsetting some of the gains from the higher velocity by slowing the bullet down over a long distance.