How does gravity affect the density and physical features of earth’s layers?

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

The cerebellum controls? thirst sensations sleep-wake cycles hand-eye coordination heart rate and pulse

The average density of the planet uranus is 1.27 103 kg/m3. the ratio of the mass of neptune to that of uranus is 1.19. the ratio of the radius of neptune to that of uranus is 0.969. find the average density of neptune.