أكاديميا - كولنز - معاجم الجيب العلمية - الفيزياء - انكليزي - فرنسي - عربي الحرف ٢_ m

Academia - Collins - Pocket Scientific Dictionaries - Physics - English - French - Arabic Letter 2_ M


magnifying lens
loupe f

magnifying glass . A simple microscope, a single telephoto lens used to generate a large, upright, imaginary image of a small object. The object should be between the pole and the focal point of the lens. Also called mag nifying glass.


manometer
manomètre

Pressure-gauge. A device used to measure pressure. The most common pressure gauges are the liquid manometer (a) below, and the Bourdon gauge (b). See also barometer used to measure air pressure.

P=PA± hpg
A liquid with density p


mass
Masse f

Mass . Measuring the amount of matter in the body, it depends on the number of particles, which does not change with gravity (gravity). Therefore, the body has the same mass on the Earth and on the Moon, while...

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It has a different weight (about one-sixth) due to the change in gravity.
To measure mass, we use a balance that does not depend on gravity (the unit is the kilogram, kg).


mass-energy
masse - energy f

Mass-energy. Einstein's theory of relativity says that there is a relationship between a body's mass and its energy. If a body gains energy, its mass increases, and vice versa.
The equation that links the change in mass m and the change in energy E is: E = mc2, where c is the speed of light in empty space, which is equal to 103 meters/second. Thus, if a reaction converts 1 milligram of mass into energy, the energy transfer is equal to 9 x 1010 joules.

Nuclear power depends on energy converted from mass changes in atomic nuclei. “The law of conservation of mass and energy” says that the total body mass and energy remain constant unless there is a transfer from or to the outside.

mass number
The number of the mass

Mass number. See nuclear number.


matter. matter
mater f

material. Anything that occupies space, or anything that is not a vacuum. Natural matter can exist in any of three states: gaseous, liquid, or solid. It is believed that matter consists of very small particles. See kinetic model.


mechanical advantage
Avantage mécanique

Mechanical benefit.
Mechanical benefit = load/effort
See force ratio.


mechanics
mechanical f

Mechanics. The branch of physics that is concerned with forces and their effects on objects. Statics deals with balanced forces, while dynamics links forces and the change in motion resulting from them. As for kinematics, it describes movement itself.
(See equations of motion)


medium
milieu m

middle. The material, or space, through which radiation is transmitted. In this context, the basic property of the medium is the speed at which radiation passes through it. See speed of sound and speed of light.
In some cases, we say that the substance that contains a magnetic field (for example) constitutes a different medium from the same substance without the magnetic field.


melting point
point m de fusion

Melting point. The temperature at which a solid turns into a liquid or at which the liquid becomes a solid, i.e. changes of state. See latent heat.