What is the vector quantity, and what is scalar? Just about the complex

Scary schoolboy two words - a vector and a scalar - are not really scary. If you approach the topic with interest, then everything can be understood. In this article, let us consider what is a vector quantity and what is a scalar quantity. More precisely, we give examples. Each student, probably, paid attention that in physics some quantities are indicated not only by a symbol, but also by an arrow from above. What do they mean? This will be discussed below. We will try to understand the difference between a vector quantity and a scalar one.

Examples of vectors. How they are denoted

What is meant by a vector? What characterizes the movement. It does not matter, in space or on a plane. What is the vector value in general? For example, an airplane is flying at a certain speed at a certain altitude, has a concrete mass, has started to move from the airport with the required acceleration. What concerns the movement of the aircraft? What made him fly? Of course, acceleration, speed. Vector magnitudes from the physics course are illustrative examples. To put it bluntly, the vector quantity is related to motion, displacement.

Water also moves at a certain speed from the height of the mountain. You see? Movement is carried out due to no volume or mass, namely speed. The tennis player allows the ball to move with a racket. It specifies the acceleration. By the way, the force applied in this case is also a vector quantity. Because it is obtained due to the given speeds and accelerations. The force is also capable of changing, of carrying out concrete actions. The wind that leaves the leaves on the trees, too, can be considered an example. Because there is speed.

Positive and negative values

A vector quantity is a quantity that has a direction in the surrounding space and a modulus. Again there was a frightening word, this time the module. Imagine that you need to solve the problem, where the negative acceleration value will be fixed. In nature, negative values, it would seem, do not exist. How can the speed be negative?

A vector has such a concept. This applies, for example, to forces that are attached to the body, but have different directions. Remember the third law of Newton, where the action is equal to opposition. The guys are pulling the rope. One team in blue T-shirts, the second in yellow. The latter turn out to be stronger. Let us assume that the vector of their force is directed positively. At the same time, the first can not pull the rope, but try. There is an opposing force.

Vector or scalar value?

Let's talk about the difference between a vector quantity and a scalar one. Which parameter has no direction, but does it matter? Let's list some scalar values below:

• Time (second, minute, day, year);
• Mass (gram, kilogram, ton);
• Length, distance (centimeter, meter, kilometer);
• Area and volume (square meter and cubic);
• Temperature (degree Celsius, Fahrenheit);
• Dose of radiation, radiation (bar, X-ray);
• Noise level, vibration (decibel).

Do they all have direction? No. What value is vector, and what scalar, can be shown only by evident examples. In physics, there are such concepts not only in the section "Mechanics, Dynamics and Kinematics", but also in the paragraph "Electricity and Magnetism." The force of Lorentz, induction, magnetic field - all these are also vector quantities.

Vector and scalar in formulas

In physics textbooks, there are often formulas in which there is an arrow from above. Remember the second law of Newton. The force ("F" with the arrow above) is equal to the product of the mass ("m") and the acceleration ("a" with the arrow on top). As stated above, the force and acceleration are vector quantities, but the mass is scalar.

Unfortunately, not all publications have a designation for these quantities. Probably, this was done for simplification, so that schoolchildren are not misled. It is best to buy those books and reference books in which the vectors in the formulas are designated.

The figure shows what value is a vector value. It is recommended to pay attention to pictures and diagrams in physics lessons. Vector quantities have direction. Where is the force of gravity directed ? Of course, down. Hence, the arrow will be shown in the same direction.

In technical universities, they study physics in depth. Within many disciplines, teachers talk about what quantities are scalar and vector. Such knowledge is required in the spheres of: construction, transport, natural sciences.