1 / 10

Physics 111: Elementary Mechanics – Lecture 12

Physics 111: Elementary Mechanics – Lecture 12. Carsten Denker NJIT Physics Department Center for Solar–Terrestrial Research. Equilibrium. The linear momentum P of the center of mass is constant. The angular momentum L about the center of mass, or about any other point, is constant.

thornton
Télécharger la présentation

Physics 111: Elementary Mechanics – Lecture 12

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Physics 111: Elementary Mechanics – Lecture 12 Carsten Denker NJIT Physics Department Center for Solar–Terrestrial Research

  2. Equilibrium • The linear momentum P of the center of mass is constant. • The angular momentum L about the center of mass, or about any other point, is constant. • Static equilibrium: and • Stable and unstable static equilibrium Center for Solar-Terrestrial Research

  3. Requirement of Equilibrium • The vector sum of all external forces that act on a body must be zero. • The vector sum of all external torques that act on a body, measured about any possible point, must also be zero. • The linear momentum of the body must be zero. balance of forces balance of torques Center for Solar-Terrestrial Research

  4. Center of Gravity • The gravitational force on a body effectively acts on a single point, called the center of gravity. • If is the same for all elements of a body, then the body’s center of gravity is coincident with the body’s center of mass. Center for Solar-Terrestrial Research

  5. Newton’s Law of Gravitation A uniform spherical shell shell of matter attracts a particles that is outside the shell as if all the shell’s mass is concentrated at its center! G = 6.67  10–11 N m2/kg2 Superposition Principle Center for Solar-Terrestrial Research

  6. Gravitation Near Earth’s Surface Gravitational acceleration • Earth is not uniform • Earth is not a sphere • Earth is rotating Mean Earth surface (0 km, 9.83 m/s2), Mt. Everest (8.8 km, 9.80 m/s2), highest manned balloon ( 36.6 km, 9.71 m/s2), Space Shuttle orbit (400 km, 8.70 m/s2), and communications satellite (35,700 km, 0.225 m/s2) Center for Solar-Terrestrial Research

  7. Kepler’s Laws • The Law of Orbits:All planets move in elliptical orbits, with the Sun at one focus. • The Law of Areas: A line that connects the planet to the Sun sweeps out equal areas in the plane of the planet’s orbit in equal times, i.e., the rate dA/dt at which it sweeps out area A is constant. • The Law of Periods: The square of the period is proportional to the cube of the semimajor axis of its orbit. Center for Solar-Terrestrial Research

  8. Center for Solar-Terrestrial Research

  9. Potential and Kinetic Energy Potential Energy Kinetic Energy Total Energy Center for Solar-Terrestrial Research

  10. Einstein and Gravitation Center for Solar-Terrestrial Research

More Related