A suction cup works by virtue of a vacuum that is created within the cup. When the cup i...

A suction cup works by virtue of a vacuum that is created within the cup. When the cup is pressed against a flat surface, most of the air is forced out, leaving a region of very low pressure. If a suction cup of area attached to a ceiling is able to support an object with a mass as large as 0.70 kg, what is the pressure inside the suction cup?