Which phrase describes an example of a model? -a microscope that is used to observe a cell
-a volcano that can explode made for a science fair project
-a review paper that explains how a plant species grows
-a news report that communicates information about climate change

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.