8. Centripetal Forces & Gravitation

Given three point masses $a$, $b$, and $c$ placed at the vertices of a right triangle with $a$ at the right angle, $b$ at distance $r$ along the x-axis from $a$, and $c$ at distance $r$ along the y-axis from $a$, what is the magnitude of the net gravitational force on mass $a$ due to masses $b$ and $c$? (Assume all masses are equal to $m$ and use $G$ for the gravitational constant.)

According to Newton's Law of Gravity, which regions on Earth receive the least direct sunlight throughout the year? $F=\frac{\mathrm{G\; m\_1\; m\_2}}{r^2}$

Which of the following best explains why $Newton’s$ Law of Gravity does not describe how a magnet can cause something to move?

According to Newton's Law of Gravity, the greater the masses of interacting objects, the $F=\frac{\mathrm{G\; m\_1\; m\_2}}{r^2}$

Which factor is most responsible for the changes in seasons on Earth according to Newton's Law of Gravity ($F=\frac{\mathrm{Gm\_1m\_2}}{r^2}$)?

Which of the following statements about the gravitational force attracting two galaxies is true?

In the context of atmospheric motion and Newton's Law of Gravity ($F=G\frac{m\mathrm{\_1}m\mathrm{\_2}}{r^2}$), which force allows the wind to cross the isobars once the forces acting on it are in balance?

Which statement best describes the difference between Newton's law of gravity and the theory of gravity?

According to the inverse square law for light, if the luminosity of the Sun is $L$ and the distance from the Sun to Earth is $d$, what is the apparent brightness $B$ of the Sun as seen from Earth?

When you are traveling down a steep hill and are using your brakes a lot, which force is primarily responsible for pulling your vehicle down the hill?

When a vehicle descends a long, steep downgrade, why should the use of brakes be considered only a supplement to the braking effect of the engine, rather than the primary means of slowing down?

According to Newton's Law of Gravity, which two factors determine the magnitude of the gravitational force between two objects ($F=\frac{G}{r^2}{m}_1{m}_2$)?