8. Centripetal Forces & Gravitation

In the context of gravitational forces in two dimensions, when is a comet's orbital speed at its maximum during its elliptical orbit around the $Sun$?

$Considering\; the\; gravitational\; force\; exerted\; by\; Earth,\; at\; which\; of\; the\; following\; locations\; would\; an\; object\text{'}s\; weight\; be\; the\; greatest?$

What is the magnitude of the gravitational force acting on the Earth due to the Sun? Express your answer in terms of the gravitational constant $G$, the mass of the Earth $M_E$, the mass of the Sun $M_S$, and the distance between them $r$.

A dam is thicker at the bottom than at the top because the pressure exerted by water increases with depth. Which of the following best explains this phenomenon?

Which statement best describes the role of gravitational forces in the formation of stars in $2$ dimensions?

Two small aluminum spheres, each of mass $0.0250\mathrm{kg}$, are separated by a distance of $80.0\mathrm{cm}$. What is the magnitude of the gravitational force between them? (Use $G=6.67\times {10}^{-11}$ $N{m}^2/{\mathrm{kg}}^2$)

Which of the following does not cause gaps in planetary rings?

What is the primary reason the Moon always keeps the same face toward the Earth?

In the context of gravitational forces in two dimensions, where is Earth's gravitational force always directed at the surface?

Which of the following is a general characteristic of the four Jovian planets in our solar system?

Which pair of forces are balanced in a state of gravitational equilibrium?

If a ball is thrown vertically upward with the same initial speed on both the Earth and the Moon, how much longer will the total time of flight (up and down) be on the Moon compared to the Earth?

When an object is in free fall near Earth's surface and air resistance is neglected, what is the only force acting on it?

The phases of the $\mathrm{Moon}$ are a result of which of the following?

Which of the following best describes the relationship between gravitational force and mass according to Newton's law of universal gravitation in two dimensions?