Question 2
When several holes are pierced at the same level low down on a bottle and it is filled with water, the water from every hole travels the same horizontal distance. Why?
The right answer is the one marked above.
The holes are all at the same level, so the pressures at them are equal. Equal pressures mean equal speeds of exit, and equal speeds mean equal horizontal distances travelled.
The diameter of a hole affects how much water comes out, but its speed is set by the pressure. The density of the water does not vary from place to place in one vessel.