Technological lesson map in physics in 7th grade.
Laboratory work No. 11 “Determination of efficiency when lifting a body along inclined plane».
| Subject | Laboratory work No. 11 “Determination of efficiency when lifting a body along an inclined plane.” |
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| Lesson type: | Lesson in the formation of initial subject skills. |
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| Target | provide training in efficiency measurement skills when lifting a body on an inclined plane. |
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| Tasks | Educational: 1. working with the textbook material and performing laboratory work, find out ways to determine the efficiency when lifting a body along an inclined plane; 2. verify from experience that useful work is less than full work; 3. deepen the theoretical and practical knowledge gained from studying the topics “Work”, “Simple Mechanisms”, “Efficiency”. Educational: 1. awaken curiosity and initiative, develop students’ sustained interest in the subject; 2. by expressing their opinion and discussing this problem, develop students’ ability to speak, analyze, and draw conclusions. 3.promote the acquisition of necessary independent skills educational activities. Educational: 1. during the lesson, help develop students’ confidence in the knowability of the world around them; 2.working in pairs of constant composition, when performing experimental tasks and discussing the problem, to cultivate a communicative culture among schoolchildren. |
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| Planned result. Meta-subject results. 1.formation of cognitive interests aimed at developing ideas about simple mechanisms; 2. ability to work with sources of information, including experiment; 3.the ability to convert information from one form to another. Subject results. 1.be able to use a ruler and a dynamometer to measure physical quantities. 2.be able to express measurement results in SI units. | Personal. Conscious, respectful and friendly attitude towards another person, his opinion; willingness and ability to conduct dialogue with other people and achieve mutual understanding in it. Cognitive. Identify and formulate a cognitive goal. Build logical chains of reasoning. Analyze and transform information. Regulatory. Ability to draw up a research plan; identify potential difficulties when solving educational problems; describe your experience, plan and adjust. Communicative. Ability to organize educational cooperation and joint activities with the teacher and peers; work individually and in a group: find a common solution and resolve conflicts based on coordinating positions and taking into account interests. |
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| Basic concepts of the topic | Complete work, useful work, efficiency, simple mechanisms, inclined plane. |
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| Organization of space |
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| Main types of educational activities of students. | Basic technologies. | Basic methods. | Forms of work. | Resources.Equipment. |
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| 1. Listening to the teacher’s explanations. 2.Independent work with the textbook. 3. Performing frontal laboratory work. 4.Work with handouts. 5.Measurement of quantities. | Collaboration technology. | 1.verbal; 2.visual; 3.practical. | Individual, whole class, in pairs of constant composition. | Physical equipment: board, ruler, dynamometer, block, tripod with coupling and foot. Resources: tests, projector, presentation. |
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Structure and course of the lesson.
| Lesson stage | Stage tasks | Activity teachers | Activity student | Time |
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| Introductory and motivational stage. |
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| Organizational stage | Psychological preparation for communication. | Provides a favorable mood. | Getting ready for work. | Personal | ||
| Analysis of independent work on the topic “Levers”. | Work on mistakes. | Problem solving. | Solve problems. | |||
| Stage of motivation and updating of knowledge(determination of the topic of the lesson and the joint goal of the activity). | Provide activities to determine lesson goals. | Offers “Think and Guess” problems, suggests naming the topic of the lesson, and defining the goal. | They are trying to answer, solve problems. Determine the topic of the lesson and purpose. | Personal, cognitive, regulatory | ||
| Operational and content stage |
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| Learning new material. 1) Updating knowledge. 2) Primary assimilation of new knowledge. 3) Initial check of understanding 4) Control of assimilation, discussion of mistakes made and their correction. | Promote students’ activities in independent study of the material. | Offers to organize activities according to the proposed tasks. 1) Suggests recalling the concept of efficiency. 2) Instruction on how to perform the work. Explanation of theoretical material. 3) Offers to complete experimental tasks. 4) suggests drawing conclusions. | Studying new material based on independent laboratory work. 1) They answer. 2) Listen. 3) Perform the proposed experimental tasks. 4) Answer questions. 5) Draw conclusions. They are discussing. | Personal, cognitive, regulatory | ||
| Reflective - evaluative stage. |
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| Reflection. (Summarizing). | An adequate self-esteem of the individual, one’s capabilities and abilities, advantages and limitations is formed. | Prompts you to select an offer. | They answer. | Personal, cognitive, regulatory | ||
| Submitting homework. | Consolidation of the studied material. | Writing on the board. | Write it down in a diary. | Personal | ||
Application.
1. Analysis independent work on the topic "Levers".
Work on mistakes.
Slide number 2.
a) Figure (a) shows a disk mounted on axis O. Forces F and F1 are applied to the disk. Name the shoulders of forces.
b) In figure (b), a person uses a lever to lift a stone weighing 600 N. With what force does a person act on the lever if AB = 1.2 m, BC = 0.5 m.
c) In figure (c), a weight weighing 20 N is placed on a ruler, one end of which rests on the table and the other is held by a dynamometer. Determine the dynamometer readings if length AC = 1 m, BC = 25 cm.
Slide number 3.
a) The figure shows a triangular plate fixed on an axis passing through point O. Forces F and F1 are applied to the plate. Name the shoulders of forces.
b) A person uses a stick to hold a bucket of water weighing 120 N. The end of the stick is on a support, while AC = 120 cm, BC = 30 cm. What force does the person apply to support the bucket?
2. Motivational stage.
Slide number 4.
"Think and guess" problems.
1. This is not only a simple mechanism, but also a military alliance.
2. This is the mechanism at the well, and a part of the shirt.
3. In this town near Moscow there is a house - a museum of P.I. Tchaikovsky.
Answers.
1. block
2. gate
3. wedge
Slide number 5.
What other simple mechanisms do you know? Why are they called that?
Inclined plane, block and lever -
We can't do without them.
3. Studying new material.
Slide No. 6-7.
An inclined plane is a simple mechanical device used to lift heavy objects to gain strength.
Inclined plane- a simple mechanism in the form of a flat surface installed at an angle other than a straight line to a horizontal surface.
Slide No. 8-10.
The characteristic of the mechanism, which determines what proportion of the useful work is from the total, is called the coefficient of performance - efficiency.
Slide number 11. Invite students to place the inclined plane at different heights. After the experiment and calculations, compare the data obtained.
Action plan for determining the efficiency of an inclined plane:
Measure the weight of the block (P).
Measure the height of the inclined plane (h).
Measure the friction force (Ftr).
Measure the length of the inclined plane (l).
8. Present the results of the work and draw conclusions.
Slide number 12.
Conclusions:
1. Useful work is less than full work.
2. The height of the inclined plane should be less than its length.
3. Efficiency is less than 100%. (At an angle of inclination of 20° to the horizon it is 45%).
4. The efficiency of an inclined plane depends on the angle of inclination. The greater the angle of inclination of the plane, the greater its efficiency.
Slide number 13.
Reflection. How did I work in class? Select an offer.
Laboratory work No. 6.
Determination of the efficiency of an inclined plane
Goal of the work:
1. calculate the efficiency of the proposed inclined plane and draw a conclusion about its value;
2. verify from experience that Ap< Аз.
Equipment: dynamometer, board, tripod, wooden block, measuring tape (or ruler), set of weights (Fig.).
Progress:
1. Determine the price of division of measuring instruments. CD = ….N. (dynamometer)
Tsl = …. N. (rulers).
2. Using a dynamometer, determine the weight of the block (R), lifting him to a height h(write in the table).
3. Moving the block at a constant speed up the inclined plane, measure the traction force required for this (F). (write in the table)
4. Use a ruler to determine the path s traversed by the lower edge of the load, and the height h, to which he was raised. (write in the table)
5. Determine the total weight of the block with two loads (R), (write in the table).
6. After loading the block with two weights and attaching a dynamometer to it, move the block at a constant speed up the inclined plane. Measure the traction force required for this ( F). s And h the same. (to table)
7. Lower the board lower and repeat experiment 2. S the same , h measure (write in table)
general task for 3 experiments:
8.
Calculate useful and expended work: 
,
9. Find the efficiency of the inclined plane. 
10. Enter the calculation results in the table.
Conclusion: as a result of our work we
Teacher activities
Student activities
Cognitive
Communicative
Regulatory
Actions taken
Actions taken
Formed methods of activity
Actions taken
Formed methods of activity
Organizational (2 minutes.)
Greets students, notes those who are absent, checks students' readiness for the lesson.
Updating knowledge (8 min.)
Displays slide 2 of the presentation “Efficiency of an Inclined Plane”. Reveals the question chosen by the student and comments on the answer given to it.
Students, one after another, choose a question number, answer it, the rest listen and analyze the given answer.
The ability to consciously construct a speech utterance in oral form and structure knowledge.
If necessary, supplement or correct this answer to the question.
Ability to listen and engage in dialogue accurately
express your thoughts, mastery of monologue and dialogic forms of speech in accordance with the norms native language.
Monitor and evaluate their own knowledge and correct it if necessary.
Developing the ability to mobilize strength and energy.
Creating a problematic situation (4 min.)
Creates and invites students to find a way out of a problematic situation:A worker needs to load a heavy barrel onto a ship. To do this, you need to apply a very large force - a force equal to the weight of the barrel. The worker cannot apply such force.
Displays slide 3 (expands scene 5).
Asks a question:Is it only the energy expended by the worker that is spent on lifting the load?
Displays slide 4 (reveals scene 3).
A cognitive goal is identified and formulated: to find a way to lift the body to a height using less force than the body weight.
Choose the most effective way to solve the problem: use an inclined plane.
It is assumed that part of the energy is spent on overcoming the friction force.
They conclude that the less energy is spent on overcoming the friction force, the more efficient the simple mechanism.
Statement and solution of the problem.
Choice of the most effective ways way out of a problem situation depending on specific conditions
Putting forward an assumption about the existence of a physical quantity that characterizes the efficiency of a simple mechanism.
They offer a way out of a problematic situation:
invite assistants, use an inclined plane.
Ability to participate in a collective discussion of a problem
They evaluate the ability to determine the work of overcoming gravity and friction, but do not know how to relate them to each other.
They set an educational task: to get acquainted with the physical quantity that characterizes the efficiency of an inclined plane.
Staging educational task based on the correlation of what is already known and what is still unknown to students.
Learning new material (8 min.)
Demonstrates lifting a body using an inclined plane, measures body weight and friction force, height and length of the inclined plane.
Displays
slides 5-6.
Gives a description of the efficiency of a simple mechanism.
Compare the weight of the body with the friction force, the height of the inclined plane with its length.
They conclude that there is a gain in strength and a loss in distance when using an inclined plane.
Draw a drawing of an inclined plane indicating its length and height, write down the definition and calculation formula for the efficiency of a simple mechanism.
Formation of sign-symbolic UUDs.
A question is asked about the units for measuring the efficiency of an inclined plane.
Development of the ability to accurately express one’s thoughts in accordance with the norms of the native language.
They identify and realize what has already been learned (calculation of the work of force) and what still needs to be learned (What work is considered useful, what work is expended, how to calculate the efficiency of an inclined plane through the work useful and expended)
Development of knowledge assessment.
Research practical work (17 min.)
Organizes a discussion of the research plan.
Displays
slides 7-11 of the presentation “Efficiency of an inclined plane.”
Provides instruction on safe laboratory work.
Formulates a problematic question:on what parameters does the efficiency of an inclined plane depend?
Distributes equipment sets, IOT, technological maps to groups of students
Assists groups of students in completing work.
Draw up a plan and sequence of actions to determine the efficiency of the inclined plane:
1. Measure the weight of the block (P).
2. Measure the height of the inclined plane (h).
4. Measure the friction force (F tr ).
Measure the length of the inclined plane (l).
Independently formulate a cognitive task:
check how the efficiency of an inclined plane depends on the weight of the body being lifted and the angle of the inclined plane?
They put forward a hypothesis: the efficiency of an inclined plane depends on the angle of inclination and does not depend on the weight of the body being lifted.
Independent creation of activity algorithms when solving search problems.
Independent formulation of a cognitive task.
Independently put forward a hypothesis about the dependence of the efficiency of an inclined plane on the angle of inclination and the weight of the body being lifted.
Monitor, adjust if necessary and evaluate the actions of the group partner.
Ability to integrate into a peer group and build productive cooperation with peers and adults
Carry out the drawn up action plan to determine the efficiency of the inclined plane:
1. Determine the price of dividing the dynamometer, protractor and measuring tape.
2. Assemble the installation.
2. Measure the weight of the block (P).
3. Measure the height of the inclined plane (h).
4. Calculate useful work using the formula.
5. Measure the friction force (F tr ).
6. Measure the length of the inclined plane (l).
7. Calculate the work expended using the formula
8. Calculate the efficiency of the inclined plane using the formula
9. Change the weight of the bar, repeat 1-6.
10. Change the angle of inclination of the plane, repeat 1-6.
11. The results are entered into the table.
Ability to draw up a plan and sequence of actions,
predicting the result.
Reflection (4 min.)
Reminds that the conclusion of the work must be a response to the purpose of the study.
They draw up the results of the work, draw conclusions, and analyze the results obtained.
Conscious construction of speech utterances in written form.
Reflection on methods and conditions of action, control and evaluation of the process and results of activity.
They conclude: during laboratory work, the efficiency of an inclined plane at an angle of inclination of 20 to the horizon turned out to be equal to 45%, it is always less than 100%, depends on the angle of inclination (the greater the angle of inclination of the plane, the greater its efficiency) and does not depend on the weight of the lifted bodies.
The ability to accurately express your thoughts;
Evaluate the results obtained:
A P must be less than Az;
The height of the inclined plane must be less than its length, the resulting efficiency must be less than 100%.
If the result obtained is not correct, an error is found in the measurement or calculations.
Ability to evaluate and control the results obtained,
adjust the plan and method of action in case of discrepancy between the standard and the result obtained.
Homework (2 minutes.)
Displays slide 12.
Back forward
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| Item: | Physics. |
| Class: | 7th grade. |
| Textbook: | Peryshkin, A.V. Physics. 7th grade [Text]: textbook. for general education textbook institutions / A. V. Peryshkin, - M.: Bustard, 2010. - 192 p. |
| Lesson topic: | Determination of the efficiency of an inclined plane. |
| The purpose of the lesson: | Introducing students to a new physical quantity - the efficiency of the mechanism. |
| Lesson objectives: | Educational:
Developmental:
Educational:
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| Planned results: | Subject: students will learn to measure the characteristics of an inclined plane, calculate useful and expended work, and the efficiency of a simple mechanism; They will find out that useful work is always less than expended and, therefore, efficiency is less than 100% and does not depend on the weight of the body being lifted, but it can be increased by increasing the angle of inclination of the plane to the horizon. Formed UUD:
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| Lesson type: | Lesson for practicing special skills. |
| Lesson format: | Research students. |
| Equipment: |
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| Materials for the lesson |
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| Author's media product: |
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| Software: | MS Office 2010, KMPlayer or another program that supports files with the swf extension. |
The lesson scenario consists of seven stages.
1. Organizational(2 min.): The teacher notes the students who are absent from the lesson, reminds those present in the lesson that they continue to study simple mechanisms and already know their definition, types, the “Golden Rule” of mechanics, the rule of lever balance, and today the children can get acquainted with one more characteristic of a simple mechanism, but after the message hidden by the puzzles is opened.
2. Updating knowledge(8 min.): The teacher displays slide 2 of the presentation for the lesson “Determination of the efficiency of an inclined plane.” The program is designed as follows: by clicking the mouse, precisely placed on the question number, the slide with the question itself opens, and the text of the question is placed on it. You can check the correctness of the answer by clicking the mouse. Using the control button, you can return to slide No. 2. By clicking on the field of a correctly answered question, the puzzle is removed and part of the message is revealed. The next question is selected and everything is repeated. It is more interesting to choose questions in a random order. After answering the last question, a message to the guys opens on the screen: “Tell me and I’ll forget. Show me and I will remember. Let me act on my own and I will learn!”
3. Creating a problematic situation(4 min.): The teacher creates and invites students to find a way out of the problem situation: a worker needs to load a heavy barrel onto a ship, but to do this, a very large force must be applied - a force equal to the weight of the barrel. The worker cannot apply such force. The guys suggest using an inclined plane. The teacher displays slide 3 of the presentation for the lesson “Determination of the efficiency of an inclined plane” (a flash model of the Unified collection of the central educational center “Simple mechanisms. Inclined plane” is inserted onto it), opens scene 5. asks the question: Is it only the energy expended by the worker that is spent on lifting the load? Students assume that part of the energy is spent on overcoming the friction force. The teacher displays slide 4 of the presentation for the lesson “Determination of the efficiency of an inclined plane” (a flash model of the Unified collection of the central educational center “Efficiency of a mechanism” is inserted on it), opens scene 3. The question of the possibility of different ratios of work performed by the mechanism is discussed , and the energy that is spent to overcome the friction force. Students make assumptions about the existence of a physical quantity that characterizes the efficiency of a simple mechanism.
4. Learning new material(8 min.): The teacher demonstrates lifting the body using an inclined plane, measures the weight of the body and the friction force, the height and length of the inclined plane. Students compare body weight with friction force, the height of an inclined plane with its length, and draw a conclusion about the gain in strength and loss in distance when using an inclined plane. The teacher displays slides 5-6 of the presentation for the lesson “Determination of the efficiency of an inclined plane” and characterizes the efficiency of a simple mechanism. Students draw a drawing of an inclined plane indicating its length and height, write down the definition and calculation formula for the efficiency of a simple mechanism.
5. Research practical work a (17 min.): The teacher organizes a discussion of the research plan. Students draw up a plan and sequence of actions to determine the efficiency of an inclined plane:
The teacher displays slides 7-11 of the presentation for the lesson “Determination of the efficiency of an inclined plane”, provides instructions on how to safely perform laboratory work, and formulates a problematic question: on what parameters does the efficiency of an inclined plane depend? Students independently formulate a cognitive task: check how the efficiency of an inclined plane depends on the weight of the body being lifted and the angle of the inclined plane? They put forward a hypothesis: the efficiency of an inclined plane depends on the angle of inclination and does not depend on the weight of the body being lifted.
The teacher distributes to students sets of instruments for performing laboratory work, instructions on labor protection ( Annex 1 ), technological map performing laboratory work No. 14 “Measuring efficiency when lifting a body along an inclined plane” ( Appendix 2 ), assists groups of students in completing work. Students perform laboratory work at different angles of inclination of the plane to the horizon and different weights of the weight being lifted.
6. Reflection(4 min.): Students evaluate and analyze the results of their work: Ap should be less than Az; The height of the inclined plane must be less than its length, the resulting efficiency must be less than 100%. If the result obtained is not correct, an error is found in the measurement or calculations. They draw up the results of the work and draw a conclusion: during laboratory work, the efficiency of an inclined plane at an angle of inclination of 20° to the horizon turned out to be equal to 45%, it is always less than 100%, depends on the angle of inclination (the greater the angle of inclination of the plane, the greater its efficiency) and not depends on the weight of the body being lifted.
7. Homework(2 min.): The teacher displays slide 12 of the presentation for the lesson “Determination of the efficiency of an inclined plane”, voices it, comments, and gives recommendations for effectively completing homework:
- § 61;
- Prepare messages (optional):
- Simple mechanisms at home, in the country.
- Simple mechanisms in construction.
- Simple mechanisms and the human body.
Addresses of used Internet resources
I. A. Izyumov,
, Municipal Educational Institution Gymnasium No. 3, Aksai, Rostov region.
Inclined Plane Efficiency Measurement
Impossible to have a direct hit from the experiment
into a narrowly defined theoretical target.
Imre Lakatos
When theory matches experiment,
This is no longer an opening, but a closing.
Pyotr Leonidovich Kapitsa
The purpose of the lesson: developing the ability to independently apply knowledge and transfer it to new conditions.
Didactic task: ensuring the assimilation of new knowledge and methods of action at the level of application in various situations.
Reflective activity of the student: self-affirmation, self-realization and self-regulation.
D Teacher’s activities to ensure reflection: presentation of educational material taking into account the zone of proximal and current development of the student.
Indicators of the actual result of solving the problem: independent completion of tasks using knowledge in various situations.
Logic of lesson construction: updating a body of knowledge → application of knowledge in various situations → control and self-control.
Equipment: wooden board, wooden block, dynamometer, measuring ruler.
During the classes
I. Updating the body of knowledge(15 minutes)
There is a reference drawing on the board. The teacher together with the students solves the problem:
How much work must be done to drag a load along a plane with an inclination angle of 30° to a height of 2 m, applying a force coinciding in direction with the displacement? Cargo mass 400 kg, friction coefficient 0.3. What is the efficiency of this?
Solution
II. Problem solving(30 min)
1 (10 min). The teacher and the class solve the problem:
Place a small object (rubber band, coin, etc.) on the ruler. Gradually lift the end of the ruler until the object begins to slide. Measure the height h and base b the resulting inclined plane and calculate the coefficient of friction.
Solution. F T x = F tr x ; mg sinα = μ F t cosα; μ = tanα = h/b.
Having received the calculation formula, students, using a wooden board, a wooden block and a ruler, experimentally determine the friction coefficient themselves and write down the result in their workbooks.
2 (10 min). The teacher and the class solve the problem:
Find the efficiency of an inclined plane 1 m long and 0.6 m high if the coefficient of friction when a body moves along it is 0.1.
Solution. Using the second result of solving the problem, we obtain:
The teacher suggests measuring the length of a wooden board and determining the efficiency of the inclined plane for the values of height and coefficient of friction obtained when solving the problem. The result is written down in a notebook.
3 (10 min). The teacher suggests determining the efficiency of an inclined plane for the height value obtained when solving the problem in one more way, and then comparing the results obtained and drawing conclusions.
Place the block on an inclined plane; Having attached a dynamometer to it, pull it evenly up along the inclined plane; measure the traction force F .
Measure gravity using a dynamometer F t acting on the block, and find the experimental value of the efficiency of the inclined plane:
Homework. Calculate the maximum possible gain in force obtained for a given plane inclination: k max = l/h.
Find experimentally the gain in force obtained using an inclined plane: k uh = F T /F.
Compare your results. Draw conclusions.
Literature
- Rymkevich A.P. Physics. Problem book-10–11: A manual for general education. institutions. – M.: Bustard, 2004.
- Dik Yu.I., Kabardin O.F., Orlov V.A., Kabardina S.I., Nikiforov G.G., Shefer N.I. Physics workshop for classes with angle. studying physics: Didact. material: grades 9–11: Ed. Yu.I. Dika, O.F. Kabardina. – M.: Education, 1993.
