Gravity

What is Newton's Law of Universal Gravitation?

Every particle in the Universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.

What two primary factors determine the strength of the gravitational force between two objects?

Masses of the two objects and the distance between their centers.

How does the mass of objects affect the gravitational force between them?

Gravitational force is directly proportional to the product of the masses. If mass increases, gravitational force increases.

How does the distance between objects affect the gravitational force between them?

Gravitational force is inversely proportional to the square of the distance between their centers. If the distance doubles, the force becomes one-fourth as strong (1/d^2).

What is the Universal Gravitational Constant (G)?

The gravitational constant (G) is a fundamental physical constant used in Newton's Law of Universal Gravitation to relate the gravitational force to the masses and distance between objects. Its approximate value is 6.674 \times 10^{-11} Nm^2/kg^2

What is the mathematical formula for Newton's Law of Universal Gravitation?

The formula for the gravitational force (Fg) between two objects is expressed as: Fg = G \frac{m1 m2}{r^2}, where G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between their centers.

What does the 'inverse square law' principle mean in the context of gravity?

It means that the strength of the gravitational force rapidly decreases as the distance between objects increases. Specifically, if the distance triples, the force becomes 1/3^2 = 1/9 as strong.

What is the difference between mass and weight according to Newton's understanding of gravity?

Weight is the measure of the gravitational force exerted on an object by a celestial body, while mass is the amount of matter an object contains. An object's mass is constant, but its weight changes depending on the local gravitational field.

What phenomena could Newton's Law of Universal Gravitation successfully explain?

It successfully explained planetary orbits, the tides, the acceleration of falling objects, and the motion of comets, providing a unified explanation for terrestrial and celestial mechanics.

What were some limitations or phenomena that Newton's Law of Universal Gravitation could not fully explain?

While highly accurate for most everyday phenomena, Newton's law breaks down under extreme conditions like very strong gravitational fields (e.g., near black holes) or at very high velocities. It also couldn't fully explain the precise orbit of Mercury, which later required Einstein's theory of general relativity.