1) The students tested how much air pressure different fruits could withstand by inserting an air pump needle and increasing the pressure until the fruit burst. 2) They hypothesized that the kiwi would withstand the most pressure according to Boyle's law, as it has the most flexible skin. 3) The fruits were categorized into skins, peels, and shells. Skins like grape and apple burst around 6 psi, peels like banana and orange around 8 psi, and shells like watermelon and cantaloupe withstood the most at around 22 psi.