A fountain pen, which has a total volume of 2.4 cm is half full with ink at ground level where the pressure is
780.0 mm Hg. It is put into the pocket of a pilot who flies to an altitude where the pressure is 520.0 mm Hg.
How much ink leaks out of the pen?

What is the independent variable in this investigation? mass volume sample number substance density

Acontrol during an experiment. might change remains constant does not exist does change

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.