A motorboat is crossing a large river. The boat's motor normally gives it a speed of 7 m/s in calm waters, but the river itself is flowing at a speed of 3 m/s. If the boat is angled perpendicular to the direction of the current, what is the overall speed of the boat?​

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.