NCERT Solutions for Class 11 Physics Chapter 8 - Gravitation

In this chapter, we will discuss the laws of gravity in detail. The chapter begins by elaborating on Kepler's laws before moving on to the universal law of gravitation. We read about the gravitational constant and its equations. We will read about acceleration due to gravity on earth and due to gravity below and above the earth's surface.

The chapter also tells us about escape speed and earth satellites. We will study the energy of an orbiting satellite and also about geostationary and polar satellites. The chapter concludes by explaining the idea of weightlessness.

• The chapter begins by giving a historical brief about the different perceived systems of motions of planetary bodies.
• The three laws of Kepler: the law of orbits, areas, and periods.
• The chapter also tells us about the universal law of gravitation and how it was found and formed.
• Equations and diagrams also portray the relationship between gravitation and mass.
• We also learn about how the gravitational constant was formed through experimentation.
• The chapter also tells us about acceleration due to the gravity of the earth, which is perceived as if the earth's entire mass is concentrated at one point for an outside object.
• This concept is further used while studying acceleration due to the gravity both below and above the surface of the earth.
• The force of gravity is conservative in nature.
• The potential energy of a body arising out of this force has also been calculated and illustrated in this chapter.
• We also learn about the escape speed of an object thrown from the earth and the pull of the moon's gravitational force on the object.
• The chapter also tells us about the earth's satellites and how they are related to Kepler's laws.
• We are also taught to calculate the energy of these orbiting satellites.
• The chapter also gives a brief explanation about geostationary and polar satellites.
• The chapter concludes by telling us about the phenomenon of weightlessness.
• This principle tells us how an object in free fall is weightless or in zero gravity.