Suppose that 6 J of work is needed to stretch a spring from its natural length of 36 cm to a length of 50 cm. (a) How much work (in J) is needed to stretch the spring from 38 cm to 46 cm?
(b) How far beyond its natural length (in cm) will a force of 45 N keep the spring stretched?

Aflask with vinegar in it has a mass of 160 grams. a balloon with baking soda in it has a mass of 40 grams. the balloon is attached to the flask to seal the opening and the vinegar and baking soda mixes. the balloon inflates to a large volume. what will the total mass of the balloon and flask be after the balloon inflates? explain. a) less than 200 grams because the solid baking soda disappears. b) 200 grams, because all the atoms remain in the balloon or flask. c) more than 200 grams because the size of the balloon is so much larger. d) less than 200 grams because gases such as the one in the balloon are lighter than solids and liquids.