Determination of the kinematic characteristics of movement using graphs. Form and conventions

Some enterprises, for objective reasons, cannot organize their work in such a way as to provide employees with days off on the same days. Then you have to change the mode of work for the entire staff or specific employees. One option would be a sliding mode.

It is necessary to distinguish between working on a staggered schedule and flexible or shift work. There are important differences that relate not only to accounting for hours worked, but also to remuneration for work. Therefore, it is important to know the features of a rolling schedule, the nuances of its preparation, as well as legal ways to transfer an employee to it.

Sliding schedule according to the Labor Code of the Russian Federation

According to the Labor Code of the Russian Federation (Article 100), an entrepreneur can set one of 4 types of workweek for staff.

Five days of work, two days off on the same days for everyone, usually at the end of the week.
Six working days with one fixed day off for all staff (most often Sunday, but other days of the week are also possible).
Working week with an incomplete number of hours (not for the entire team).
Flexitime.

There is no separate section of the Labor Code of the Russian Federation devoted to a rolling schedule, but it is mentioned in the context of the types of workweek in Article 100.

sliding mode they call such a schedule in which rest days are not fixed, move and fall on any day, including public holidays; at the same time, the total duration of the accounting period (week, month, quarter) should be identical to the usual schedule.

INFORMATION NOTE! Flexible work schedule is regulated by art. 102 of the Labor Code of the Russian Federation, and work in shifts - Art. 103 of the Labor Code of the Russian Federation.

Sliding schedule: specifics

What does the expression "chart slides" mean? Within the framework of such a regime, the days intended for rest “move” along the calendar. This does not happen randomly or at the choice of the employee, but is fixed in advance by a plan. For example, in one week the employee rests on Wednesday and Friday, and the next - on Tuesday and Thursday.

Remains relevant in sliding mode time tracking, summing up the hours worked for a particular period selected for accounting. The time cycle for which the working hours will be added up is set individually at each enterprise, which is fixed in the local regulations of the company: it is legitimate to choose a week, month, quarter or even a year for this purpose.

IMPORTANT! The amount of time worked cannot exceed the amount of hours provided for by law, that is, 40 per week in terms of the accounting period. If the hours worked, which turned out to be less due to the fault of the scheduler (the employee is “underloaded”), the rate must still be paid in full.

Drawing up a rolling schedule

An employee cannot be imposed a certain mode of work without his consent. Possible options for the legal application of a staggered schedule provide for the goodwill of the employee and his consent to this form of employment. Let's consider them.

Flexible scheduling for employment. If a person is hired for a job that is characterized by a rolling schedule, his right is to agree to such working conditions or not. He should read about this feature of his future regime in the employment contract. By signing this document, he thereby assumes the obligation to comply with the schedule established for him.
Installing a sliding schedule. It happens that the mode of transferring days off is caused by production necessity, then the authorities must notify the employee about this and obtain his consent in writing. The change of the schedule is carried out by drawing up an additional agreement to the employment contract.
Appointment of working days and days off. In the sliding mode, the schedule is drawn up for the period selected by the accounting period. For preliminary acquaintance of employees with it, it is no longer necessary to observe certain deadlines. It is sufficient if the schedule is known before the accounting period. The employee no longer has the power to change it at his own discretion or refuse to go to the workplace on any days. However, in order to avoid conflicts and difficult situations, it is advised to acquaint the staff with the upcoming regime in advance, preferably a month in advance.

Everyone has a day off, and you have a work schedule

If your schedule is rolling, forget that usually the weekend falls on the weekend. It may turn out this way, or it may not - it all depends on how the schedule was planned. If Saturday or Sunday turned out to be intended for work, nothing can be done, this is a feature of a rolling schedule. They are considered regular workdays and are paid accordingly. An additional day of rest is not provided. The employee does not have the right to refuse to go to his workplace on this day.

NOTE! Some types of employees, such as mothers of toddlers under three years of age, have advantages over work schedules. But not in those cases when their signature is under the consent to the sliding mode: there are no exceptions for them, that is, they will have to work on any day of the week that turned out to be working according to the schedule.

And what about the holidays?

Official non-working days adopted within the country are also by no means always days off for workers on a sliding regime.

Art. 113 of the Labor Code of the Russian Federation prohibits assigning work on these days, however, there are exceptions to this law:

the inability to suspend work due to production needs;
work related to servicing people, provided for by the relevant list (for example, transport employees, doctors, emergency responders, etc.);
the signature of the employee himself, indicating his consent (taking into account the opinion of the trade union).

If an employee with a staggered schedule falls on a public holiday, they will have to work it out. But the status of a holiday cannot be canceled, so it should be paid at a double rate or provide an additional day off on some other day (by agreement).

Employee Benefits

On holidays, if they turned out to be working, employees with special statuses have the right to refuse to work:

disabled people;
mothers of children up to three years of age.

For them, it is better to plan the work schedule so that they do not have to work on official holidays. But if for some reason it is difficult, and they themselves do not mind going on a work shift on such a day, this is possible, if it is not contraindicated for them for health reasons. At the same time, the authorities must enlist their signature on the document that they are aware of their right to refuse.

ATTENTION! An additional order, which is usually issued to attract employees to work on holidays, is not needed in this case: its role is played by a signed agreement on a rolling schedule or its establishment under an employment contract.

Flexible, changeable or sliding

In business and personnel practice, these concepts often cause confusion and confusion.

We see that they are regulated by various articles of the Labor Code, which means that they have serious differences in documenting, payment and accounting approach.

Comparison with flexible schedule

Sometimes the terms "flexible" and "sliding" charts are used interchangeably. In some legislative acts, especially those that have not undergone significant changes since Soviet times, this is directly reflected in the title, for example, Decree of the USSR State Committee for Labor and the Secretariat of the All-Union Central Council of Trade Unions dated 06.06.1984 No. conditions for the use of a sliding (flexible) work schedule for women with children.

However, these two types of graphs cannot be identified. It would be more correct to say that any is a sliding one, but not any sliding schedule is necessarily flexible.

Sliding and changeable graphics

The shift schedule is characterized by continuous production and a work shift of several shifts per day. The output in this mode also shifts, which is the reason why it is confused with the moving one. But with a shift schedule, the weekend shift occurs when the total accounting of working time for the accounting period shows processing (part 3 of article 111 of the Labor Code of the Russian Federation).

Differences between a sliding schedule and a flexible and shift schedule

The main distinguishing features of these three types of working time organization are shown in Table 1.

№	Base	Flexitime	Flexible schedule	Shift work
1.	Start and end of the working day	According to work schedule	Can be rescheduled at the discretion of the employee	According to shift schedule
2.	Holiday work	Full-time, if it falls on the schedule, is usually paid	In agreement with the employee	Paid at double rate or compensated for extra days off
3.	Time tracking	Total - for the reporting period should not exceed the number of hours established by the Government.
4.	Introduction to the chart	There are no specific time frames	Negotiated between employee and employer	Not less than a month
5.	Is it possible to refuse to work on a certain day	It is forbidden	Can	Can be replaced by another working day (“swap shifts”)

Mechanical movement is represented graphically. The dependence of physical quantities is expressed using functions. designate

Graphs of uniform motion

Time dependence of acceleration. Since the acceleration is equal to zero during uniform motion, the dependence a(t) is a straight line that lies on the time axis.

Dependence of speed on time. The speed does not change with time, the graph v(t) is a straight line parallel to the time axis.

The numerical value of the displacement (path) is the area of the rectangle under the speed graph.

Path versus time. Graph s(t) - sloping line.

The rule for determining the speed according to the schedule s(t): The tangent of the slope of the graph to the time axis is equal to the speed of movement.

Graphs of uniformly accelerated motion

Dependence of acceleration on time. Acceleration does not change with time, has a constant value, graph a(t) is a straight line parallel to the time axis.

Speed versus time. With uniform motion, the path changes, according to a linear relationship. in coordinates. The graph is a sloping line.

The rule for determining the path according to the schedule v(t): The path of the body is the area of the triangle (or trapezoid) under the velocity graph.

The rule for determining the acceleration according to the schedule v(t): The acceleration of the body is the tangent of the slope of the graph to the time axis. If the body slows down, the acceleration is negative, the angle of the graph is obtuse, so we find the tangent of the adjacent angle.

Path versus time. With uniformly accelerated movement, the path changes, according to

The work of hired workers in different areas of economic activity implies absolutely diverse schedules of their involvement in the work process. If office workers work, as a rule, in the conditions of a five- or six-day work week, then, for example, the service sector requires a completely different regime. A schedule is drawn up for each employee, which may include night work, shifts, and “floating” days off. In the meantime, it is impossible to draw up a schedule, guided only by the employer's and employee's own wishes - there are a lot of rules that are enshrined in labor legislation.

What is the mode of work, what elements does it consist of

Hours worked - the basis for remuneration for employees with a time-based payment condition

The labor law obliges the employer to keep a strict record of working time for each employee, because it is for the time (with the exception of rather rare cases of piecework) that the work is paid. The mode of labor is determined primarily by law, and secondly by the employer in agreement with the trade union and the employee, the rules for the distribution of time. The Labor Code of the Russian Federation contains a section on labor time, a separate chapter of which (Chapter 16) regulates the regime.

Working hours according to the Labor Code of the Russian Federation can be represented by several varieties in terms of their duration: normal, reduced and incomplete. In addition, special varieties are night work, overtime work, work with the possibility of an irregular day. The main difference between part-time and reduced hours is their payment - the first means payment in proportion to the time worked, the second - regardless of the time worked. Night and overtime work are paid at an increased rate, irregular working hours, as a rule, are compensated by additional days of the annual vacation period.

The elements of the working time regime are those positions that, in accordance with the law, must be determined when forming the regime for each worker. Among these main positions, the Labor Code of the Russian Federation calls:

duration (number of working days) of the week (for example, five-day or six-day, incomplete, indicating the number of days, etc.);
the presence of a condition on irregular working hours;
duration of daily work - the number of hours of a working day or shift with an exact indication of their beginning and end, time frames for breaks;
number of shifts per day;
rules for alternating working and free days (for example, “two workers in two days off”, etc.).

How and by what documents the labor regime is determined

The work schedule for each individual employee must be negotiated with him in advance - when concluding an employment agreement. In general, according to the organization in the context of structural divisions or positions, the mode of operation is determined in the internal labor regulations.

PWTR is a local NPA of an organization that determines the main points of relations between a team of employees and an employer - the rules for hiring and terminating labor relations, the powers and obligations of the parties to a labor agreement in the course of work, general conditions regarding the working time regime, etc. The PWTR is approved by the employer in agreement with the trade union organization, each employee must be familiarized with this document in writing when concluding an employment contract.

In the PWTR, the working time regime of an organization can be reflected in the following way:

establishing the duration of the work week and specific daily work time frames for certain groups of positions (for example, “For departments: Management, Human Resources, Legal Service, Accounting, Office - a five-day work week, the beginning of the work day is 8:00, the end of the work day - 17:00, break for rest and meals - from 13:00 to 14:00");
establishing for certain positions the conditions for an irregular working day, indicating the amount of compensation in the form of additional days (at least three) of leave in accordance with Art. 119 of the Labor Code of the Russian Federation (for example, “For positions: Director, Deputy Director, driver - an irregular working day is established with compensation in the form of 4 days of an additional vacation period annually”);
establishing a work schedule for individual departments and positions (for example, “For the sales department, a work schedule is established in compliance with the labor standard for a five-day 40-hour work week”);
establishing a summarized accounting of working hours for individual positions (for example, “For the position “Seller”, a summarized accounting of working hours is established, the accounting period is a quarter”);
the establishment of a flexible work schedule, a night (equivalent to daytime) work regime, a shift schedule, the division of the working day into parts for certain categories of workers (for example, “For the position of“ Cashier ”, a shift work schedule is established, in which the third shift attributable to night hours is equated to daytime working hours).

The labor agreement must contain a section on the working regime. For employees whose position involves working on a regular five- or six-day work week, the agreement specifies the exact work schedule. For those who will work according to the schedule, with a summarized account, with an irregular working day, with part-time work, with dividing the day into parts, etc., these circumstances should be reflected in the specified agreement. Cases of establishing an unspecified working time regime are illegal, such a violation may entail liability for the employer under Art. 5.27 of the Code of Administrative Offenses of the Russian Federation with all the ensuing consequences (fines and other sanctions).

A section on working hours must be included in the contract

How to establish new regime rules in an organization: order and documents

If an employee gets acquainted with an already existing regime for a separate position when hiring by signing an employment agreement and a mark on reading the PWTR, then changing the current regime is somewhat more complicated.

The decision to change the PVTR can be issued in the form of an order

The order of the procedure is as follows:

To begin with, the manager must make an informed decision about which positions or structural units the new rules are introduced for.
Then, according to all the rules for changing the local regulatory legal acts, the corresponding changes are made to the PWTR (the project must be agreed with the trade union within five days, then signed by the head).
On the basis of the changed PWTR, each employee who is affected by the changes is warned about a change in the essential working conditions (a notice against signature should be given no later than a month before the issuance of the order). In case of refusal to continue the employment relationship under the changed conditions, the employee must be dismissed after the expiration of the notice period.
Within the prescribed period (one month after notifying employees), an order is issued for the enterprise to change the regime for specific employees (at this stage they must be listed by name). Each worker gets acquainted with the order against signature.
On the day the administrative document is issued, an additional agreement to the contract is concluded with each employee, changing the conditions for the working hours.
From the date specified in the additional agreement and order, a new regime begins its operation with its new documentary design (for example, with scheduling).

Work schedule as a document that regulates the individual mode of work on a daily basis

The work schedule is one of the most important documents for organizing the work of those employees who do not work according to the general (production) calendar. So, the schedule every day regulates the time of coming to work, leaving work, the time of breaks, and even the workplace assigned to the employee.

The schedule is drawn up, as a rule, for one month, however, this period is not regulated by law. Therefore, depending on the circumstances and characteristics of the production process, the document can be drawn up for a week, and for a quarter, and for a year.

A graph, as a document, can be drawn up:

simultaneously for all employees of the enterprise;
for employees of one structural unit;
for a certain group of employees from different structural divisions;
separately for one employee.

Form and conventions

In the shift schedule, it is enough to indicate only the designation of the shift

In case of summarized accounting, the graph must contain columns reflecting the sum of hours per month, per quarter (depending on the accounting period)

Scheduling and Approval Process

The procedure for drawing up and approving a schedule in an organization can be regulated either by a local regulatory legal act or by order of the head. The persons responsible for the maintenance, endorsement and approval of the document are determined by designating them in these documents and entering the corresponding item in the job description.

As a rule, the schedule is drawn up by the person responsible for this in the structural unit (department, service), endorsed by the head of the structural unit, a representative of the personnel department and the trade union, and approved by the head of the enterprise or his deputy in charge of the relevant area of activity.

The schedule can be drawn up both manually (using standard Office tools with output to paper), and in specialized software systems (for example, "1C: personnel and salary", SAP, etc.).

Schedule Requirements

When scheduling work, the employer is in a situation where it is necessary to comply with a lot of rules, requirements and interests. First of all, these are the requirements of labor legislation that protects the rights, interests and even health of the employee:

The duration of daily work should not exceed the established Art. 94 of the Labor Code of the Russian Federation of limits (special boundaries are established for minor employees, disabled people, workers in harmful unsafe conditions).
The number of working hours per week should not exceed the norm according to the production calendar (40 hours - as a general rule). For those who have a summarized accounting for the accounting period, it is imperative to comply with the norm of hours of this accounting period (quarter, month, etc.).
Shifts, predominantly at night, should be reduced by 1 hour.
After a shift lasting more than 24 hours, the same or more rest period is provided.
If the condition for dividing the working day into parts is not established for the employee, his lunch break (or the sum of several during the day) should not last more than two hours.
The minimum lunch break is 30 minutes. It is obligatory to establish daily, if the agreement of the parties and the PWTR does not provide for the employee to eat in parallel with work. The lunch break is not paid.
It is forbidden to work during two shifts following one after the other.
Hours falling on the period of illness or vacation of an employee are also taken into account in his monthly (quarterly) rate. In other words, the employee is not required to complete the actually missed hours to the norm.
It is impossible to exceed the limits established by Art. 99 of the Labor Code of the Russian Federation for overtime work (no more than four hours in a two-day working period, no more than one hundred and twenty hours a year), etc.

Of course, when forming the schedule, the operating mode of the enterprise, the load standards, and the interests of the employee himself are taken into account.

Familiarization of employees

The employer is obliged to familiarize the employees with the work schedule no later than one month before the day it comes into effect - this is a direct requirement of Art. 103 of the Labor Code of the Russian Federation. Violation of this deadline threatens with administrative liability.

In order to avoid violating the requirements of the law, it is necessary to start drawing up a schedule no later than one and a half months before the start of the accounting period. For example, the schedule for December should be drawn up before October 15 in order to have time to agree on it, approve and familiarize all employees (after all, some of them may be on vacation or on sick leave at the time of familiarization, but this circumstance is not an excuse in case of violation of the terms of familiarization ).

How to change the established work schedule

Since the work schedule is established by agreement of both parties to labor relations, then any of them can become the initiator of its change. Changing the regime (as a more general, permanent concept) at the initiative of the employer is described in the section on establishing the labor regime at the enterprise. A change in the schedule, as a one-time event or an event relating to one employee, occurs:

or by adjusting an already drawn up schedule (document), if the employee is set to work according to the schedule;
or by amending the employment agreement - if the employee works according to the regime fixed in this document (that is, according to the usual production calendar).

In the first case, the scheduler, at the request of the employee or on his own initiative (due to production needs), draws up a corrective schedule, endorses and approves it according to the usual procedure for preparing this document.

You can change the working hours both for a group of employees and for one of them (for example, at his request due to family circumstances)

In the second case, at the request of the employee, an order is prepared to change the working hours - this is enough if the schedule changes for up to two weeks. If the period of changing the working regime is longer, it is necessary to conclude an additional agreement to the contract.

If the work schedule changes for more than two weeks, it is necessary to conclude an additional agreement to the employment contract

Establishing a work schedule and scheduling for employees is one of the employer's primary tasks in the field of organizing the labor process. And this is no easy matter. The schedule must correspond not only to the production needs of the company, but also to the conditions defined by the legislator. In addition, it is extremely important to familiarize employees with the schedule in time in order to avoid possible sanctions from state bodies exercising control in the field of labor relations.

I have a higher legal education, work experience in court, bank, at an enterprise. Despite the fact that my main specialization is criminal law and procedure, all my professional activities are related to commercial law, ranging from personnel issues to lending problems. For a long time I have been writing reviews of foreign and domestic media on business topics.

« Physics - Grade 10 "

What is the difference between uniform motion and uniformly accelerated motion?
What is the difference between a path graph for uniformly accelerated motion and a path graph for uniform motion?
What is called the projection of a vector on any axis?

In the case of uniform rectilinear motion, you can determine the speed according to the graph of coordinates versus time.

The velocity projection is numerically equal to the tangent of the slope of the straight line x(t) to the x-axis. In this case, the greater the speed, the greater the angle of inclination.

Rectilinear uniformly accelerated motion.

Figure 1.33 shows graphs of the projection of acceleration versus time for three different values of acceleration in a rectilinear uniformly accelerated motion of a point. They are straight lines parallel to the x-axis: a x = const. Graphs 1 and 2 correspond to movement when the acceleration vector is directed along the OX axis, graph 3 - when the acceleration vector is directed in the direction opposite to the OX axis.

With uniformly accelerated motion, the velocity projection depends linearly on time: υ x = υ 0x + a x t. Figure 1.34 shows the graphs of this dependence for these three cases. In this case, the initial speed of the point is the same. Let's analyze this chart.

Acceleration projection It can be seen from the graph that the greater the acceleration of the point, the greater the angle of inclination of the straight line to the t axis and, accordingly, the greater the tangent of the angle of inclination, which determines the value of acceleration.

For the same period of time at different accelerations, the speed changes by different values.

With a positive value of the acceleration projection for the same time interval, the velocity projection in case 2 increases 2 times faster than in case 1. With a negative value of the acceleration projection on the OX axis, the velocity projection modulo changes by the same value as in case 1, but the speed is decreasing.

For cases 1 and 3, the graphs of the dependence of the velocity modulus on time will coincide (Fig. 1.35).

Using the speed versus time graph (Figure 1.36), we find the change in the coordinate of the point. This change is numerically equal to the area of the shaded trapezoid, in this case, the change in coordinate for 4 with Δx = 16 m.

We found a change in coordinates. If you need to find the coordinate of a point, then you need to add its initial value to the found number. Let at the initial moment of time x 0 = 2 m, then the value of the coordinate of the point at a given moment of time, equal to 4 s, is 18 m. In this case, the displacement module is equal to the path traveled by the point, or the change in its coordinates, i.e. 16 m .

If the movement is uniformly slowed down, then the point during the selected time interval can stop and start moving in the opposite direction to the initial one. Figure 1.37 shows the projection of velocity versus time for such a motion. We see that at the moment of time equal to 2 s, the direction of the velocity changes. The change in coordinate will be numerically equal to the algebraic sum of the areas of the shaded triangles.

Calculating these areas, we see that the change in coordinate is -6 m, which means that in the direction opposite to the OX axis, the point has traveled a greater distance than in the direction of this axis.

Square above we take the t axis with the plus sign, and the area under axis t, where the velocity projection is negative, with a minus sign.

If at the initial moment of time the speed of a certain point was equal to 2 m / s, then its coordinate at the moment of time equal to 6 s is equal to -4 m. The module of point movement in this case is also equal to 6 m - the module of coordinate change. However, the path traveled by this point is equal to 10 m - the sum of the areas of the shaded triangles shown in Figure 1.38.

Let's plot the dependence of the x-coordinate of a point on time. According to one of the formulas (1.14), the time dependence curve - x(t) - is a parabola.

If the point moves at a speed, the time dependence of which is shown in Figure 1.36, then the branches of the parabola are directed upwards, since a x\u003e 0 (Figure 1.39). From this graph, we can determine the coordinate of the point, as well as the speed at any given time. So, at the moment of time equal to 4 s, the coordinate of the point is 18 m.

For the initial moment of time, drawing a tangent to the curve at point A, we determine the tangent of the slope α 1, which is numerically equal to the initial speed, i.e. 2 m / s.

To determine the speed at point B, we draw a tangent to the parabola at this point and determine the tangent of the angle α 2 . It is equal to 6, therefore, the speed is 6 m/s.

The path versus time graph is the same parabola, but drawn from the origin (Fig. 1.40). We see that the path is continuously increasing with time, the movement is in one direction.

If the point moves at a speed whose projection versus time graph is shown in Figure 1.37, then the branches of the parabola are directed downwards, since a x< 0 (рис. 1.41). При этом моменту времени, равному 2 с, соответствует вершина параболы. Касательная в точке В параллельна оси t, угол наклона касательной к этой оси равен нулю, и скорость также равна нулю. До этого момента времени тангенс угла наклона касательной уменьшался, но был положителен, движение точки происходило в направлении оси ОХ.

Starting from the time t = 2 s, the tangent of the slope angle becomes negative, and its module increases, which means that the point moves in the opposite direction to the initial one, while the module of the movement speed increases.

The displacement modulus is equal to the modulus of the difference between the coordinates of the point at the final and initial moments of time and is equal to 6 m.

The graph of dependence of the path traveled by the point on time, shown in Figure 1.42, differs from the graph of the dependence of displacement on time (see Figure 1.41).

No matter how the speed is directed, the path traveled by the point continuously increases.

Let us derive the dependence of the point coordinate on the velocity projection. Velocity υx = υ 0x + a x t, hence

In the case of x 0 \u003d 0 and x\u003e 0 and υ x\u003e υ 0x, the graph of the dependence of the coordinate on the speed is a parabola (Fig. 1.43).

In this case, the greater the acceleration, the less steep the branch of the parabola will be. This is easy to explain, since the greater the acceleration, the smaller the distance that the point must travel in order for the speed to increase by the same amount as when moving with less acceleration.

In case a x< 0 и υ 0x >0 speed projection will decrease. Let us rewrite equation (1.17) in the form where a = |a x |. The graph of this dependence is a parabola with branches pointing downwards (Fig. 1.44).

Accelerated movement.

According to the graphs of dependence of the projection of velocity on time, it is possible to determine the coordinate and projection of the acceleration of a point at any moment in time for any type of movement.

Let the projection of the speed of a point depend on time as shown in Figure 1.45. It is obvious that in the time interval from 0 to t 3 the movement of the point along the X axis occurred with variable acceleration. Starting from the moment of time equal to t 3 , the motion is uniform with a constant speed υ Dx . From the graph, we see that the acceleration with which the point moved was continuously decreasing (compare the angle of inclination of the tangent at points B and C).

The change in the x coordinate of a point over time t 1 is numerically equal to the area of the curvilinear trapezoid OABt 1, over time t 2 - the area OACt 2, etc. As we can see from the graph of the dependence of the velocity projection on time, you can determine the change in body coordinates for any period of time.

According to the graph of the dependence of the coordinate on time, one can determine the value of the speed at any moment of time by calculating the tangent of the slope of the tangent to the curve at the point corresponding to the given moment of time. From figure 1.46 it follows that at time t 1 the velocity projection is positive. In the time interval from t 2 to t 3 the speed is zero, the body is motionless. At time t 4 the speed is also zero (the tangent to the curve at point D is parallel to the x-axis). Then the projection of the velocity becomes negative, the direction of movement of the point changes to the opposite.

If the graph of the dependence of the velocity projection on time is known, it is possible to determine the acceleration of the point, and also, knowing the initial position, determine the coordinate of the body at any time, i.e., solve the main problem of kinematics. One of the most important kinematic characteristics of movement, speed, can be determined from the graph of the dependence of coordinates on time. In addition, according to the specified graphs, you can determine the type of movement along the selected axis: uniform, with constant acceleration, or movement with variable acceleration.