The elevation at ground level is 0 feet an elevator starts 90 feet below ground level. after traveling for 15 seconds the elevator is 20 feet below ground level. which statement describes the elevator rate of change in elevation during this 15 second interval

Every 15 seconds it travels 70 feet. Hope this helps!!

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.