This relationship is the basis of most astronomical mass determinations. Circular speed is the orbital speed of a body that moves in a circular orbit. The circular speed at a given orbital distance has the same value as the average orbital speed for an elliptical orbit having a semi-major axis equal to the circular distance. A body moving at escape velocity leaves the solar system on a parabolic path and never returns. At any distance from the Sun, escape velocity is the square root of 2 times the circular speed at that distance.
Tidal forces are differences in gravitational force.
They occur because the various parts of a body are in different directions and at different distances from the object attracting them. Tidal forces stretch the body in the direction toward and away from the attracting object. The strongest tidal forces are felt by large bodies near massive attractors. Key Term acceleration. acceleration of gravity angular. Practice quize with true answer 1.