10 th class 1st chapter gravition notes
Answers
Topics to be learn :
Gravitation, Circular motion and centripetal force, Kepler’s laws, Newton’s universal law of gravitation, Acceleration due to the gravitational force of the Earth, Free fall, Escape velocity.
Types of forces :
Gravitational force: There exists a force of attraction between any two particles of matter in the universe such that the force depends only on the masses of the particles and the separation between them. It is called the gravitational force and the mutual attraction is called gravitation.
The gravitational force between the earth and the moon. The gravitational force is a universal force, i.e., it acts between any two objects in the universe.
Electromagnetic force: The force between two charged particles in motion.
Nuclear force: The force between a proton and a neutron in the nucleus of an atom.
Centripetal force : In uniform circular motion of a body, the force acting on the body is directed towards the centre of the circle. This force is called centripetal force.
Thus, a force acts on any object moving along a circle and it is directed towards the centre of the circle. This is called the centripetal force. ‘Centripetal’ means centre seeking, i.e., the object tries to go towards the centre of the circle because of this force.
Example : The moon revolves around the earth due to the gravitational force exerted on it by the earth. This force is directed towards the centre of the earth and is thus a centripetal force.