9th Science NCERT Chapter 9

– Gravitation

Summary: Objects in the universe attract each other with a force proportional to their masses and inversely proportional to the square of the distance between them. This force is called the gravitational force.

– Universal Law of Gravitation

Summary: States that every object in the universe attracts every other object with a force that depends on their masses and the distance between them. The force acts along the line joining the centers of the objects.

– Motion of Objects Under the Influence of Gravitational Force of the Earth

Summary: All objects, regardless of their size or mass, fall from a height at the same rate under the influence of gravity. Air resistance affects the rate at which objects fall.

– Acceleration Due to Gravity

Summary: Acceleration due to gravity is the acceleration experienced by objects falling towards the Earth. It is denoted by 'g' and has a constant value of 9.8 m/s^2 near the Earth's surface.

– Archimedes’ Principle

Summary: Archimedes' principle states that objects immersed in a fluid experience an upward force equal to the weight of the fluid displaced by the object. This principle explains why some objects float while others sink in fluids.

These are the important topics and their corresponding summaries from the chapter provided in the file "9th Science NCERT Chapter 9.pdf"【4:0†source】.