Liquid Dropper

[Ron]

How does a liquid/medicine dropper suck in liquid? To some extent, I guess I know the answer but am not sure. When the bulb of the liquid dropper is squeezed, it forces out all the air from the dropper which creates a low air pressure inside the dropper. When the liquid dropper is immersed in the liquid & the bulb of the dropper is released, outside air pressure forces the liquid inside the liquid dropper but why does the outside air pressure force the liquid to go inside the dropper?

 

Thanks,

 

Ron

[swansont]

If there is a pressure differential, there is a force (since P = Force/Area), and this gets transmitted through the fluid.