If you see a hot air balloon is rising above the top of the hill what is the top of the hill called

The answer to your question is,

The top of the hill is called the reference point. As you can reference the top of the hill as where you are. :)

-Mabel <3

a small object of mass 3.66 g and charge -17.6 µc is suspended motionless above the ground when immersed in a uniform electric field perpendicular to the ground. what are the magnitude and direction of the electric field?

are there answer choices to this question? this seems like a question where you have options to choose from.