Two words frightening a schoolboy - a vector and a scalar - are not really scary. If you approach the topic with interest, then everything can be understood. In this article, we consider which quantity is vector and which is scalar. More precisely, we give examples. Each student, probably, noticed 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 figure out how the vector value differs from the scalar one.
Examples of vectors. How are they denoted
What is meant by a vector? What characterizes the movement. It doesn’t matter in space or on a plane. What is vectorial in general? For example, a plane flies at a certain speed at a certain altitude, has a specific mass, started moving from the airport with the desired acceleration. What relates to the movement of an airplane? What made him fly? Of course, acceleration, speed. Vector quantities from the physics course are illustrative examples. Speaking directly, the vector quantity is associated with movement, displacement.
Water also moves at a certain speed from the height of the mountain. See? The movement is not due to volume or mass, but rather to speed. A tennis player allows the ball to move with a racket. It sets the acceleration. By the way, the force applied in this case is also a vector quantity. Because it is obtained due to given speeds and accelerations. Strength can also change, carry out specific actions. The wind, which sways the leaves on the trees, can also be considered an example. Since there is speed.
Positive and negative values
A vector quantity is a quantity that has a direction in the surrounding space and a module. A frightening word appeared again, this time a module. Imagine that you need to solve a problem where a negative acceleration value will be fixed. In nature, negative values would not seem to exist. How can speed be negative?
A vector has such a concept. This applies, for example, to forces that are applied to the body but have different directions. Recall Newton’s third law, where action equals counteraction. The guys are pulling the rope. One team in blue t-shirts, the second in yellow. The second are stronger. Suppose that the vector of their force is directed positively. At the same time, the former cannot pull the rope, but they are trying. A counteracting force arises.
Vector or scalar value?
Let's talk about how the vector value differs from the scalar one. Which parameter has no direction, but has its own meaning? We list some scalar values below:
- time (second, minute, day, year);
- weight (gram, kilogram, ton);
- length, distance (centimeter, meter, kilometer);
- area and volume (square meter and cubic meter);
- temperature (degrees Celsius, Fahrenheit);
- dose of radiation, radiation (bar, x-ray);
- noise level, vibration (decibels).
Do they all have a direction? No. Which value is vector and which is scalar can only be shown with illustrative examples. In physics, there are such concepts not only in the section "Mechanics, Dynamics, and Kinematics", but also in the section "Electricity and Magnetism". Lorentz force, 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 on top. Remember the second law of Newton. The force ("F" with the arrow above) is equal to the product of mass ("m") and acceleration ("a" with the arrow above). As mentioned above, force and acceleration are vector quantities, but mass is scalar.
Unfortunately, not all publications have a designation of these quantities. Probably, this was done to simplify, so that students are not misled. It is best to buy those books and directories in which the vectors in the formulas are indicated.
The magnitude is vector, the illustration will show. It is recommended to pay attention to pictures and diagrams in physics lessons. Vector quantities have a direction. Where is gravity directed ? Of course, down. So, the arrow will be shown in the same direction.
In technical universities they study physics in depth. In many disciplines, teachers talk about which values are scalar and vector. Such knowledge is required in the areas of: construction, transportation, natural sciences.