Final answer:
Air pressure helps fill a syringe with medicine. When you pull up the plunger, the air pressure inside the syringe decreases compared to the atmospheric pressure, causing the medicine to move from the area of higher pressure into the syringe.
Step-by-step explanation:
The process of filling a syringe with medicine involves the principle of air pressure. When you pull up the plunger of a syringe, a vacuum is created inside the barrel. This reduces the air pressure inside the syringe. As a result, the medicine, which is under higher atmospheric pressure, gets pushed into the syringe to equalize the pressure, effectively 'filling' the syringe with medicine.
This principle is demonstrated in Boyle's law, which states that the pressure and volume of a gas have an inverse relationship in a closed system. When the volume inside the syringe increases (due to pulling the plunger), the pressure decreases, causing the medicine to move from an area of higher pressure (the medicine vial) to an area of lower pressure (the syringe).
In everyday life, this principle is also seen when pumping air into a tire. The air moves from the high-pressure pump to the lower pressure inside the tire. Hence, air pressure plays a significant role in many aspects of our lives, including the process of filling a syringe with medicine.
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