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

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


velocity(v)
vitesse f

Speed. The speed of an object is its displacement per unit time, and its unit is meters per second, m/s. To get the speed, we divide the displacement s by the time taken v=s/t. Speed ​​is a vector.
Compare with speed.
The slope of the displacement/time graph at any point gives us the velocity at that moment.
See -equa tions of motion.


velocity ratio
Rapport m de vitesses

Speed ​​ratio. See distance ratio.


speed, relative
vitesse f relative

Relative speed. When two objects are moving, each has a speed relative to the other. In each case, it is how the body appears to move when viewed from the other body.

Note that VAB, i.e. the velocity of A with respect to B, is equal and opposite to VBA. The figure below shows two cases of this type.
See Doppler effect.

VA.B = 30 m/s east

VB.A = 30 m/s west


vernier
vernier m

Vernier. A device that allows a more accurate reading of length
Ruler.


vibration
vibration f

vibration. Concussion. Regular back and forth movement. Examples of this include the “ringing” of a ruler on the edge of a table and the movement of a pendulum. Such movements are common in physics. See sound sources.

In all cases, motion can be shown as a pure sine wave (simple vibration or simple harmonic motion) or as the sum of two or more sine waves.


vibrator
vibration m

Shaking. A rod that vibrates when supplied with direct or alternating current through an electromagnet. DC types can act as an oscillator. The vibrations produce sound waves.

virtual image
image f virtuelle

Fake image. See image.


viscosity
Viscosite f

Viscosity. Measurement of fluid's refusal to flow. The better expression is fluid friction. Air resistance is a form of viscosity. Syrups are more viscous than water. Good car engine oil is viscous-static, meaning that its viscosity does not change much when the engine warms up. The falling body in the viscous medium accelerates until the downward force of gravity equals the upward force of viscosity. Then a constant limit speed is reached.


vision defects
Anomalies fpl view

Vision defects. A normal eye can see light coming from any object at a distance of more than about...
250 mm.

A short-sighted eye can see nearby objects but cannot clearly see distances of more than a few metres. A distancing lens can correct this defect.

As for the long-sighted eye, it cannot focus on nearby objects. The telephoto lens corrects this defect. See fees below.
There are other vision defects.
See, for example, color vision.


voltage
tensionf

Voltage. A common name between potential electromotive difference and electromotive force difference, and its unit in both cases is the voltage V. The potential difference is the electrical pressure that pushes electrical charges through the circuit.
One volt is the difference in potential between two points that allows one joule of energy to be obtained when a charge equal to one coulomb moves between the two points.

Voltage = joules/coulombs

V = W / Q = VIt / It


volume (V)
volume m

size. The space occupied by a sample of a substance. Its unit is the cubic meter (m3). The size of a sample in the form of building stone is equal to the product of length multiplied by width and height. The volume of the ball is equal to 4/3r3, where r
It is the radius (or radius). The volume of a gaseous sample depends on temperature and pressure.
See: gas laws.
On the other hand, the volumes of solid and liquid samples are largely constant.