Chapter 13 Gravitation
► 13-1 What Is Physics? ► 13-2 Newton's Law of Gravitation ► 13-3 Gravitation and the Principle of Superposition ► 13-4 Gravitation Near Earth's Surface ► 13-5 Gravitation Inside Earth ► 13-6 Gravitational Potential Energy ► 13-7 Planets and Satellites: Kepler's Laws ► 13-8 Satellites: Orbits and Energy ► 13-9 Einstein and Gravitation
13-1 What Is Physics?
► Understand the gravitational force-the force that holds you to Earth, holds the Moon in orbit around Earth, and holds Earth in orbit around the Sun.
► The gravitational force also reaches across intergalactic space, holding together the Local Group of galaxies.
► The gravitational force also reaches across intergalactic space, holding together the Local Group of galaxies.
► This force is also responsible for some of the most mysterious structures in the universe: black holes.
13-2 Newton's Law of Gravitation
13-3 Gravitation and the Principle of Superposition
Example:
13-4 Gravitation Near Earth's Surface
Example:
Example:
The Earth:
► 1. Earth's mass is not uniformly distributed.
► 2. Earth is not a sphere. Earth is approximately an ellipsoid, flattened at the poles and bulging at the equator.
► 3. Earth is rotating.
► At equator:
Example:
Shell Theorem:
► A uniform shell of matter attracts an external particle as if all the shell's mass were concentrated at its center.
Example: Gravity Force Inside a Spherical Shell
13-5 Gravitation Inside Earth
13-6 Gravitational Potential Energy
► Potential energy and force:
Gravitational Field:
13-7 Planets and Satellites: Kepler's Laws
The Second Law:
The Third Law:
13-8 Satellites: Orbits and Energy
Example:
All Earth geosynchronous orbits, whether circular or elliptical, have a semi-major axis of 42,164 km (26,199 mi).
Scape Speed:
Example:
13-9 Einstein and Gravitation
► Einstein's View of Gravitation Einstein pointed out that gravitation and acceleration are equivalent. This principle of equivalence led him to a theory of gravitation (the general theory of relativity) that explains gravitational effects in terms of a curvature of space.
Curvature of space
Gravitational Lensing
Dark Matter
Example:
Example:
Example:
Example:
