Two students are setting up an experiment to find the average velocity of one of their pet goldfish swimming from one side of its tank to the other. which of the following measurements will they need to make in order to calculate the average velocity?     a)the distance across the fish tank, and the final velocity of the goldfishb) the final velocity of the goldfish, and the time it took  c)the distance across the fish tank, and the time it took  d)the final velocity of the goldfish, and the mass of the goldfish save