The force of attraction between all masses in the universe, especially the attraction of the earth's mass for bodies near its surface is called ________.

CONCEPT:

• Newton's law of Gravitation: It states that everybody in this universe attracts every other body with a force, which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
  • The direction of the force is along the line joining the particles.
  • The gravitational force was discovered by Sir Issac Newton.

The magnitude of the gravitational force F is given by:

\(F = G\frac{{{M_1}{M_2}}}{{{R^2}}}\)

Where G = universal gravitational constant, M1 = mass of 1st body, M2 = mass of 2nd body, and R = distance between the two bodies.

EXPLANATION:

1.  Spring force: The force applied when a spring is compressed or extended is called spring force.
2. Mechanical force: The force in which there is direct contact between the bodies is called mechanical force. For example Friction force, tension force, etc.
3. The force which pulls the body towards earth is called gravitational force. So option 3 is correct.
4. The Frictional force is the opposing force that is created between two surfaces that try to move in the same/opposite directions. 

EXTRA POINTS:

• The Four Fundamental Forces of Nature are:

1. Gravitational force, 2. Weak Nuclear force, 3. The electromagnetic force, 4. and Strong Nuclear force.

• Gravitational force is the weakest force in nature.
• The nuclear force is the strongest force in nature