Orders of magnitude of distances from Earth to a few stars and galaxies in the Universe or duration of propagation of light corresponding.
- Sound travels in matter media (solid, liquid and gas) and it does not spread into space. Sounds too intense have implications for the hearing.
A necessary condition for vision: the entrance of light into the eye.xistence de deux types de sources de lumière : Rectilinear propagation of light The light beam. Sun-Earth-Moon Phases of the Moon, eclipses: simplified interpretation. It heats up and transfers part of the energy received from outside the form of heat.
Colored lights and color of objects First notions of colored lights: - As a filter; - Continuous spectrum; - Superposition of colored lights. Lenses: homes and pictures Principle of image formation in geometrical optics.
Speed of light and sound, signal propagation - The light can propagate in a vacuum and in transparent media like air, water and glass.
Speed of light in vacuum (3x108 m / s or 300,000 km / s).
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The sum of its kinetic energy of position and is its mechanical energy. - Kinetic energy and road safety The kinetic energy: the relationship giving the kinetic energy of a solid translation is: Ec = 1 / 2 m.v². The braking distance is growing faster than the speed.
- Forces, work and energy - FORCES AND MOTION - Motion of a rigid body 1. Third law : The principle of reciprocal actions - MAGNETISM.
ELECTROMAGNETIC FORCES Magnetic field Action of a magnet, a current, a very short needle.
- Characteristics of the intermediate image and final image by building and / or application forms of conjugation. Modeling of the telescope by an afocal system of two thin lenses and modeling of a Newton telescope with a mirror system, thin lenses : - Graphical construction of the intermediate image and the image of an object plane perpendicular to the optical axis. Gravitation governs the whole universe (solar system, stars and galaxies).
- Characteristics of the intermediate image and final image by building and / or application forms of conjugation. Weight and mass Remote action exerted by the Earth on an object in its neighborhood: weight of a body.