When a horizontal syringe squirts a liquid through the needle:
A) the pressure inside the needle is less than in the barrel near the plunger
B) the pressure inside the needle is higher than in the barrel near the plunger
C) the pressure is the same everywhere in the fluid
D) Bernoulli's equation is not applicable because the syringe is horizontal
To determine the correct answer, we can consider the principles of fluid dynamics and Bernoulli's equation.
Bernoulli's equation states that in a flowing fluid, the total pressure at any point is the sum of the static pressure, the dynamic pressure, and the potential energy per unit volume. It is applicable to both horizontal and vertical flow situations.
In the case of a horizontal syringe squirting a liquid through the needle, the flow of the liquid is generally considered to be laminar, meaning that the fluid flows smoothly without turbulence.
Within the fluid, the pressure is not uniform, and it decreases as the fluid velocity increases, according to Bernoulli's equation. This decrease in pressure is due to the conservation of energy.
So, the correct answer to the question is A) the pressure inside the needle is less than in the barrel near the plunger. As the liquid is forced through the narrow needle, its velocity increases, resulting in a decrease in pressure according to Bernoulli's equation.
Therefore, to arrive at this conclusion, we need to understand the principles of fluid dynamics and Bernoulli's equation. By considering the fluid flow and the changes in pressure due to velocity, we can determine that the pressure inside the needle is lower than in the barrel near the plunger.