Gravitational force: action and reaction

In summary, gravitational force is a natural phenomenon that causes objects with mass to attract each other. It is based on the principle of mass attracting mass and is responsible for the motion of planets, stars, and other celestial bodies. The force decreases as the distance between two objects increases and is described by the inverse square law. Gravitational force follows Newton's Third Law, where the action is the force of attraction and the reaction is the equal force in the opposite direction. While it cannot be canceled out, it can be counteracted by other forces.
  • #1
mark_ch
1
0
Consider two particles 1 and 2 that can interact with each other but are isolated from their surroundings. If an internal force from particle 1, for example, a gravitational force, acts on particle 2, then there must be a second internal force—equal in magnitude but opposite in direction—that particle 2 exerts on particle 1.
But if the particle 2 exerts a gravitational force too? Will the net force exerted on particle 1 be the sum of the gravitational forces 1 to 2 and 2 to 1?
 
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  • #2
the force is given by

[tex]F=G \frac{m_1 m_2}{r^2}[/tex]

the force on 1 = - force on 2

so F1= -F2
 
  • #3


Yes, the net force exerted on particle 1 will be the sum of the gravitational forces from particle 2 to 1 and from particle 1 to 2. This is because according to Newton's third law of motion, for every action, there is an equal and opposite reaction. In this case, the gravitational force between the two particles is considered an internal force, meaning it is a force between two objects within the system and does not involve any external forces. Therefore, the net force on particle 1 will be the sum of the internal forces acting on it, which includes the gravitational force from particle 2.
 

1. What is gravitational force?

Gravitational force is a natural phenomenon that causes objects with mass to attract each other. It is one of the four fundamental forces of nature and is responsible for the motion of planets, stars, and other celestial bodies.

2. How does gravitational force work?

Gravitational force is based on the principle of mass attracting mass. The more massive an object is, the greater its gravitational force. The force also depends on the distance between two objects, with the force decreasing as the distance increases.

3. What is the difference between action and reaction in gravitational force?

Action and reaction refer to Newton's Third Law, which states that for every action, there is an equal and opposite reaction. In gravitational force, the action is the force of attraction between two objects, and the reaction is the equal force of attraction between the two objects in the opposite direction.

4. How does distance affect gravitational force?

The force of gravitational attraction between two objects decreases as the distance between them increases. This relationship is described by the inverse square law, which states that the force is proportional to the inverse of the square of the distance between the objects.

5. Can gravitational force be canceled out?

No, gravitational force cannot be canceled out. It is a fundamental force of nature and is always present between two objects with mass. However, the force can be counteracted by other forces, such as the centrifugal force caused by the rotation of a planet around its axis.

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