Girl tosses a stone into the air with an initial upward velocity of 8.00 meters/second and hears the splash when it hits the water 4.20 seconds later. how deep is the water level in the well below where she tossed the stone? use 343 meters/sec

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.