M3.4 Synthèse – Poids et Masse et Gravitation

Study Notes

Loi de la gravitation universelle: Two objects with mass exert an attractive force on each other, called universal gravitation. This force is responsible for the movement of celestial bodies and the fall of objects. This force increases with the masses of the objects and decreases with the distance between them. The formula for this force is F = G * m1 * m2/d^2, where G is the gravitational constant.
Expression mathématique de la force d'attraction gravitationnelle: The gravitational force exerted by one body on another is expressed mathematically as F = G * m1 * m2 / d^2. The force is proportional to the product of masses and inversely proportional to the square of the distance between their centers. The Force is directed along the line joining the two centers of mass.
Importance of Gravitational Force: Gravitational force is significant for large masses like planets and stars.
The Weight and Mass: Weight (P) and mass (m) are different physical quantities. Mass is the amount of matter in an object, a measure of the inertia. Weight, on the other hand, is the force exerted on an object due to gravity (gravitation). Weight depends on the local gravity, while mass does not. Mass is measured in kilograms (kg) and weight in Newtons (N). The relationship between weight and mass is given by the equation P = m * g.

The gravitational force exists between any two bodies with mass, although it's only noticeable for large masses (like planets or stars or very large bodies).
Units of Measurement: The gravitational constant (G) has units of N⋅m²/kg². Mass is measured in kilograms (kg), distance (d) in meters (m), and force in Newtons (N).
Variation of Gravitational Force: Gravitational force decreases with increasing distance.