Lesson summary on the topic of the speed of rectilinear motion. Theme of the lesson: "Rectilinear uniform motion

Lesson 2/4

Subject. Rectilinear uniform motion

The purpose of the lesson: to acquaint students with the characteristic features of the rectilinear movement of an evenly accelerated

Lesson type: combined

Lesson plan

Knowledge control		Independent work "Reference system, trajectory, path and displacement"
Demonstrations		Rectilinear uniform motion
Learning new material		1. The speed of rectilinear uniform motion. 2. Displacement in the case of rectilinear uniform motion. 3. Equation for the coordinate in the case of rectilinear uniform motion
Consolidation of the studied material		1. Problem solving. 2. Security questions

STUDY NEW MATERIAL

The simplest form of mechanical motion is uniform rectilinear motion. Students are already familiar with this type of movement from the course of physics and mathematics of previous classes.

Ø Rectilinear uniform motion is such a motion when a material point makes the same movements for any equal time intervals.

One of the main kinematic characteristics of movement is speed:

Ø The speed of rectilinear uniform movement is a physical quantity equal to the ratio of movement to the time interval t, during which this movement occurred.

As we can see from the definition, speed is a vector quantity: the direction of speed coincides with the direction of movement. In the case of rectilinear uniform motion, the displacement modulus s coincides with the path l, so in this case we can write that

The unit of speed in SI is 1 m/s.

Ø 1 m / s is equal to the speed of such a rectilinear uniform movement, at which a material point moves a distance of 1 m in 1 s.

Question to the students during the presentation of new material

1. Give examples of rectilinear uniform motion.

2. Shows the speed of the body in the case of rectilinear uniform motion?

3. Is it possible to assert that a body moves uniformly in a straight line if it:

a) every second a distance equal to 1 m passes;

b) moves along a straight line in one direction and covers a distance of 2 m in every second?

4. Which speed is greater: 1 m/s or 3 km/h?

CONFIGURATION OF THE STUDYED MATERIAL

Homework

G1) - 3.10; 3.12; 3.13; 3.16;

р2) - 3.26; 3.27; 3.28, 3.31;

d3) - 3.73, 3.74; 3.76; 3.77.

LESSON № 2 Grade 9

Subject: Uniform rectilinear motion.

Lesson type: Learning new material

Lesson Objectives:

To acquaint students with the characteristic features of rectilinear uniform motion. Formulate the concept of speed as one of the characteristics of the uniform motion of a body.

Teach students to calculate displacement in uniform rectilinear motion.

LESSON PLAN

Lesson stages

Action

1. Organizing moment

Class readiness for the lesson

2. Repetition of the previous material

Repetition of previous material

3. Studying new material

Learning new material

4.Fixing the material

Fixing the material

5. Homework

Homework

During the classes

Org.moment

(Student greeting)

2. Reviewing previous material and checking homework

At the beginning of the lesson, students are tested on their knowledge of:writing a test paper on the theory of the studied material:

I option

What is called material point?

the train moves from Barnaul to Biysk;
passengers are boarding.

What coordinate system

the plane is flying;
a person is moving in an elevator;
football player on the field.

What trajectory, path, movement?

In what cases is the projection of displacement onto the axis positive, in which is it negative?

What movement is called uniform?

II option

What reporting system?

In what cases can a person's car be considered material point? Explain why.

the engine is being repaired;
the vehicle is moving.

What coordinate system you choose when solving the following tasks:

tram traffic;
submarine in the ocean;
car racing.

What's the Difference way from displacement?

Define speed of uniform rectilinear motion.

In what cases is the projection of the speed of uniform motion on the axis positive, in which is it negative?

Learning new material

Uniform rectilinear movement called such a movement occurring along a rectilinear trajectory, in which the body (material point) makes the same movements for any equal time intervals.

The movement of a body in rectilinear motion is usually denoteds . If the body moves in a straight line in only one direction, the modulus of its displacement is equal to the distance traveled, i.e.|s|=s . To find the displacement of a bodys for a period of timet , you need to know its displacement in unit time. For this purpose, the concept of speed is introduced.v of this movement.

The speed of uniform rectilinear motion called a constant vector quantity equal to the ratio of the movement of the body to the time interval during which this movement was made:

v=s/t. (one)

The direction of speed in rectilinear motion coincides with the direction of movement.

Since in uniform rectilinear motion for any equal time intervals the body makes equal displacements, the speed of such motion is a constant value (v=const). Modulo

v=s/t. (2)

From formula (2) set the unit of speed.

The SI unit of speed is1 m/s (meter per second); 1 m/s is the speed of such a uniform rectilinear motion at which a material point moves 1 m in 1 s.

Velocity - a vector quantity - has a direction. The direction of speed is the same as the direction of motion. Speed can be constant or variable

Speed units

in SI : [ v ] =

Multiples: 1 km/h = 3.6 m/s; 1 km/s = 1000 m/s

Longitudinal: 1 cm/s = 0.1 m/s; 1 dm/s = 0.1 m/s

Let the axis Oh coordinate system associated with the reference body coincides with the straight line along which the body moves, andx 0 is the coordinate of the starting point of the body motion. Along axisOh directed and movings, and speed v moving body. From formula (1.1) it follows thats=vt . According to this formula, the vectorss and v*t are equal, therefore their projections on the axis are also equalOh :

s x =v x t. (3)

Now you can establish the kinematic law of uniform rectilinear motion, i.e., find an expression for the coordinates of a moving body at any time. Insofar asx=x 0 +s x , taking into account (3) we have

x=x 0 + v x t. (4)

According to formula (4), knowing the coordinatex 0 starting point of body movement and body speedv(her projection v x per axle Oh ), at any time you can determine the position of the moving body. The right side of formula (4) is an algebraic sum, since andX 0 , and v x can be both positive and negative.

Graphical representation of the velocity projection:

V x , m/s

t , c

S x =V x *t

V x , m/s

t , c

S x =V x *t

V x >0

V x <0

S x >0

S x <0

x, m

Graphical representation of the equation of motion:

x=x 0 + v x t

x 0

t, s

x=x 0 -v x t

Fixing the material.

vx, km/h

-70

t ,with

Construct graphs of the projection of velocity vectors versus time for two cars moving in a straight line and uniformly, if one moves at a speed of 50 km/h, and the other moves in the opposite direction at a speed of 70 km/h.

Questions on fixing the material:

What is called uniform motion?

How to find the projection of the displacement vector of the body, if the projection of the speed of movement is known?

What sign can the projection of the velocity vector have, and what does this sign depend on?

5. Homework.

Subject. Rectilinear uniform motion.

Goals:

educational:

to form knowledge about uniform motion, speed and displacement of rectilinear uniform motion, solving the basic problem of mechanics for rectilinear uniform motion;

educational:

to instill a desire to master new knowledge;

developing:

to develop the thinking skills of students, the ability to work independently.

Equipment: projector, screen, laptop, task cards.

During the classes.

I . Organizational moment.

II. Checking the assimilation of the studied material.

Independent work (short-term).

Ioption	IIoption
1. The ball fell from a height of 4 m, bounced off the floor and was caught at half the height. What is the path and movement of the ball?	1. The boy threw the ball up and caught it again. Find the path and displacement of the ball if it rose to a height of 2.5 m.
	2. The figure shows the trajectory of the body from A to B. Find the projection of the movement on the coordinate axes, displacement.
1 D BUT 0 1 3 5 7 x,m	3. The figure shows the trajectory of the body from A to D. Find the path traveled, displacement, projections of displacement on the coordinate axes. 1 B A 0 1 3 5 7 x,m

III. Motivation of educational activity.

The simplest form of mechanical motion is uniform rectilinear motion.

A car moves uniformly in a straight line along a straight section of the road without acceleration and braking, a parachutist after opening a parachute in calm weather.

Since the trajectory of motion is a straight line, it is sufficient to choose a one-dimensional coordinate system to describe the motion.

To solve the basic problem of mechanics, you need to know how to find the displacement

uniform rectilinear motion.

IV . The topic of the lesson.

(Write down the topic of the lesson in your notebook)

V. Learning new material.

A uniform movement is one in which the body any makes equal movements in equal intervals of time.

Let the bus cover 120 km in every 2 hours. But it is impossible to say that the bus moves evenly, since in 1 hour it travels 57 km, and in the next 1 hour - 63 km. This is the meaning of the word "any" .

Characteristic movement is speed.

The speed of uniform movement, taught in the 7th grade, is equal to the ratio of the path to the time during which the body passed this path.

Having introduced the physical quantity displacement, we formulate the definition of speed as follows: the speed is equal to the ratio of the displacement to the time of this displacement.

moving

c crust = -------

time

But from the point of view of mathematics, a vector (displacement) multiplied by a scalar (1/time) results in a vector.

So, speed- vector quantity. Since time cannot be negative, the velocity and displacement vectors point in the same direction.

Let's write it down in a notebook (look at the screen).

Speed - vector : =

and to one side.

In SI: [ 𝑣 ] =

The speed of uniform rectilinear motion is a constant value both in absolute value and in direction.

Graphical dependence of speed on time:

Let's write in a notebook (see on the screen).

𝒗 x ,

𝒗 x 0 ("right")

0 t ,with

𝒗 x

Moving uniform rectilinear motion equals: = t.

Let's write it down in a notebook (look at the screen).

moving = t.

dependency graph S = v t by analogy with y = kX, where v and k - constants - a straight line passing through the origin.

Let's write it down in a notebook (look at the screen).

S , m 1 1; 2- "to the right": 𝒗 1 𝒗 2

0 t ,with

3 3- "left"

Coordinate of uniform rectilinear motion: x = x ₀ + 𝒗 x t.

Let's write it down in a notebook (look at the screen).

x coordinate = x ₀ + 𝒗 x t - OZM decision.

Dependency graph by analogy with y \u003d b + k x. If b = 0, then the line passes through the origin.

Let's write it down in a notebook (look at the screen).

x, m 1 1; 2; 3- "to the right": 𝒗 1 𝒗 2; 𝒗 2 = 𝒗 3

4 4- "left"

3; 4:x 0 is 0

one; 2:x 0 not equal to 0

Let's write it down in a notebook (look at the screen).

The geometric meaning of movement.

𝒗 x ,

0 t t , with

displacement = area shapes (rectangle) under the chart

VI. Consolidation of the studied material.

1. What movement is called uniform rectilinear?

2. The physical meaning of the speed of uniform rectilinear motion.

3. How is the velocity vector directed?

4. What is the graph of the speed of uniform rectilinear motion?

4. What is the displacement graph of uniform rectilinear motion?

5. What is the graph of the coordinates of uniform rectilinear motion?

VII. Homework.

Lesson Objectives : formulate signs of uniform motion.

During the classes.

I. Organizing time.

II. Checking homework

What is point movement?

What is the reference body?

How can you set the position of a point?

What is a radius vector?

III. Learning new material.

Speed is a vector quantity. It is considered given if its modulus and direction are known. Let's define speed.

In rectilinear motion, the speed does not change in direction. The movement is called uniform rectilinear if the trajectory is a straight line and the point passes equal movements in any equal time intervals.

Experiment

Conclusion: behind

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Preview:

PLAN - SUMMARY OF A PHYSICS LESSON IN GRADE 10

Lesson topic:

"Uniform rectilinear motion".

Lesson Objectives: formulate signs of uniform motion.

During the classes.

Organizing time.
Checking homework

What is point movement?

What is the reference body?

How can you set the position of a point?

What is a radius vector?

Learning new material.

Speed is a vector quantity. It is considered given if its modulus and direction are known. Let's define speed.

The speed of uniform rectilinear motion is a value equal to the ratio of its movement to the time interval during which this movement occurred.

Uniform rectilinear motion is a motion in which the body makes equal displacements for any equal intervals of time.

Experiment

Conclusion: for the body makes equal displacements in equal intervals of time.

The displacement during uniform rectilinear motion of the body along the X axis in time t can be calculated:

EQUATION OF UNIFORM RECTILINEAR MOTION IN COORDINATE FORM.

- EQUATION OF UNIFORM RECTILINEAR MOTION IN VECTOR FORM.

V X \u003d (X-X 0 ) / t - SPEED.

Problem solving

1. The movement of a truck is described by the equation x1=-270+12t, and the movement of a pedestrian along the side of the same highway is described by the equation x2=-1.5t. Make an explanatory drawing (direct the X axis to the right), on which indicate the position of the car and the pedestrian at the initial moment of time. At what speed and in what direction did they move? When and where did they meet?

2. According to the given graphs, find the initial coordinates of the bodies and the projections of the velocities of their movement. Write the equations X(t). According to the schedule, find the time and place of the meeting.

Homework

§7-8, p.22 exercise 1(1)

Outline of a physics lesson in grade 7 "Schedule of uniform rectilinear motion"

Author: Ganovicheva Maria Anatolyevna, Municipal state institution "Secondary school No. 13" of the akimat of the city of Ust-Kamenogorsk, teacher of physics.

Purpose: exchange of experience with colleagues on the organization of educational activities of students in physics lessons.
Description: This abstract is intended for teachers of physics during the initial acquaintance and study of the topic "Graph of uniform rectilinear motion." The material has a close relationship with the subject of mathematics, so it can be used to conduct an integrated lesson.

The purpose of the lesson: familiarity with the equation and a graphical method for describing rectilinear uniform motion.
Tasks:
Tutorials:
To teach how to read and build graphs of rectilinear uniform motion for various bodies (moving with negative and positive speed, with and without an initial coordinate);
Developing:
Develop an understanding of the meaning of physical quantities;
Develop functional literacy, namely: the ability to compare, analyze, use formulas, record data in tabular and graphical form, perform calculations;
Educational:
To cultivate cognitive interest in the subject, attentiveness and observation, to strengthen interdisciplinary connections,
Cultivate a culture of making notes in notebooks;
Develop the ability to work independently and in a team.

Lesson type: lesson of studying and primary consolidation of new knowledge.
Interdisciplinary communication: mathematics, geography, technology, drawing.
Devices and materials: handout: coordinate systems, task cards ( see Appendices 1,2); presentation "Graph of uniform rectilinear motion", illustrations, posters on the topic of the lesson.

During the classes:

1. Organizational moment.
Preliminary organization of the class (checking absent, jobs).
I want to start our lesson with the phrase of N. Rothschild: "Who owns the information, he owns the world."
In order to possess information or information about something, one must be able to receive it.
How can information be received and transmitted?
Student responses: In words, text, tabular, depict with a diagram or drawing, draw in the form of a graph.

Read the topic of the lesson, think what What do we have to do in class today? How?
Student responses: get acquainted with graphs, compare movement, build graphs.
You have already met with a graphical way of presenting information: weather forecasts, a class graph (it is easy to see subjects for which there are a lot of good grades), a cardiogram, comparative stock reports.

Working with graphs is very convenient and useful and will be useful to us in the future.

2. Actualization of the studied material.
We answer questions:
1. What does the science of physics study?
Physics is the science of nature that studies the most general forms of motion of matter and their mutual transformations.
2. What is called mechanical movement?
The mechanical motion of a body is the change in its position in space relative to other bodies over time.
3. What is called a trajectory?
The line described in space by this point as it moves.
4. What is speed? Speed is a constant value equal to the ratio of the movement of the body to the time during which the movement occurred
5. Calculation formula
6. Name the types of movement according to the figure
A) along the trajectory: rectilinear or curvilinear B) along the speed: uniform or non-uniform

The simplest type of movement: rectilinear uniform (the path is equal to the displacement, the speed is constant), which we met in the last lesson.
Using the example of such a movement, we will begin to work with one of the ways to describe and study physical processes - graphic way.

3. Learning new material.
Today we will recall from the course of geography the concept coordinate .
Geographical coordinates- quantities that determine the position of a point on the earth's surface using latitudes and longitudes.
Coordinate in physics also a numeric value indicating where the point is at a given time.
Designated - X, measured in meters.

When calculating and constructing, it is important to take into account the reference system.
That is, at the moment of the beginning of the movement, the body can be at the point that we take as the origin (its coordinate will be “o”) or it can be displaced and have - X0 the initial coordinate.

The equation of rectilinear uniform motion allows us to solve the main problem of mechanics - to find the position of the body at any time.
Please note that the speed and the initial coordinate do not change, the coordinate and time will change in the equation.
From the course of mathematics, we know a similar equation - this is the equation of a straight line (linear dependence):
Therefore, graphically both dependencies will look the same.
We build the abscissa axis and the ordinate axis. The teacher supervises the performance by students of all stages of work in notebooks.
The axes must be signed not only with values, but also with units of measurement.
To build a graph of rectilinear uniform motion, you need to know at least two points. It is customary to write numerical values in the form of a table next to the coordinate axes.

Example 1
Let's build a graph of the monitor lizard movement if it is known that it moves from the origin of coordinates and its speed is 3 m/s.

Next, students are given a sheet with completed axes and a table for the speed of further work.
(Appendix 1)

Example 2
Let's build a motion graph if it is known that a cyclist is moving at a speed of 5 m/s from a point with an initial coordinate of 10 m.

The example of the movement of a cyclist shows us how important it is to choose the right scale for the image on the graph.
In geography, this is the ratio of the length of a segment on a map or plan to its actual size. In drawing and technology, this is the ratio of the dimensions of an object in a drawing to its actual dimensions.
For us today scale is the ratio of the sizes of physical quantities on a conditional graphic image.
In one cell, we can accept both 1 m and 2 m and 5 m and 10 m vertically. Horizontally, you can take 0.25s, 0.5s, 1s or more.

Example 3:
Let's build a graph of the movement of the helicopter in the same coordinate system, if it is known that it is moving at a speed of -20m/s from a point with an initial coordinate of 15m.

4. Consolidation of the studied material
Students are grouped into groups of 3. Groups are formed by the teacher, taking into account abilities and psychological compatibility. The task involves discussion and joint implementation: plotting two (and if there is enough time, more) bodies on one sheet.
One student performs the graphic part of the task: builds axes, selects a scale, finds points and connects them, signs the work.

Two other students receive task cards (Annex 2) perform calculations and complete tables. After completing the task, you need to evaluate your work in the group for each participant.
For strong students, additional tasks should be provided. For example, if the group had cards No. 1 and 2, then in case of quick completion, these students can be offered more cards No. 3 and 4.

5. Summing up.
The verbal or textual form of information transmission, which is not always familiar to us, is the most effective.
What have we learned today and what have we learned?
Children's answers: In this lesson, we learned how to describe the DRP graphically, build, compare and understand graphs; use formulas, record data in tabular and graphical form, perform calculations; correctly draw up notes in notebooks; work independently and in a team, understood the relationship of physics with other sciences.
And now let's, everyone will think and evaluate their collective work.

Self-esteem. Correct solutions are posted on the board.

Submit your grades on the group sheet.