36 Comparison of the gravitational and electrostatic fields

Long-term plan section: Section Electrostatics electric field

School:

Date: _______________________

Name of teacher:

Class: 10 ____

Количество присутствующих: ______

отсутствующих: ____

Lesson Topic

Comparison of the gravitational and electrostatic fields

Learning objectives which are pursued in this tutorial (link to curriculum)

10.3.1.3 - compare features of gravitational and electrostatic fields;

Lesson Objectives

Students will be

- enumerate three similarities between gravitational and electrostatic field;

- enumerate three differences between gravitational and electrostatic field.

Criteria for success

Students can:

- enumerate three similarities between gravitational and electrostatic field;

- enumerate three differences between gravitational and electrostatic field.

- apply a similarity between formulas for finding the characteristics of gravity and versa electric fields.

Language objectives

Vocabulary and terminology specific to the subject:

Students can:

Students can name the similarities and differences between the gravitational and electrostatic fields.

Subject vocabulary and terminology:

Mass, charge, field, field lines, field strength, direction of field lines, field power characteristic, field energy characteristic.

A series of useful phrases for dialogue / writing:

Mass / charge creates a field in the surrounding space, the lines of which ... ...

A uniform field is called a field ... ... ...

The power characteristic of the field is ... ...

Instilling values

Humanity

Throughout the lesson, instill openness, cooperation, respect, tolerance in relationships with classmates through work in pairs

The imparting of values is carried out through / through discussion of the key points of the topic in groups.

Interdisciplinary communication

Relationship with mathematics: working with formulas, with graphs, physical quantities and their units of measurement.

Key Skills

Critical thinking

Preliminary Knowledge

The charge, mass, intensity of gravitational and electric fields, field lines, Coulomb's law, the law of the world.

Lesson Proper

Scheduled Lesson Stages

Scheduled Lesson Activities

Resources

Beginning

8 min.

At the beginning of the lesson, the teacher suggests that the students, working in pairs, determine the truth and falsity of the statements.

Students in pairs will pull out one statement and determine its truth.

Statements:

1. The electric and gravitational fields are described by two characteristics: force and energy.
2. Unlike gravitational fields, electric fields are force fields that act upon the direct contact of two charged objects.
3. When creating a field with a point charge or mass, the force of the electric field decreases faster with increasing distance than the force from the side of the gravitational field.
4. The magnitude of the acceleration of a moving charge in a uniform electric field depends only on the magnitude of its charge and mass.
5. The magnitude of the interaction force between two bodies having a mass does not depend on the environment in which they are located.
6. The Coulomb's law is one of the basic laws of electrostatics, which determines the magnitude of the interaction force of two point charges.
7. The field strength created by several bodies is a vector sum of the field strengths created by these bodies separately.
8. The electric field strength is a force characteristic of the electric field, which is a scalar quantity.
9. The potential energy of the body, raised to a certain height above the zero level, is numerically equal to the work that the attraction force does when the body falls from a given height to the zero level.
10. The change in the potential energy of a charged body, when moving in a uniform electric field, depends on the shape of the trajectory along which the body moves.

Ключ: 1. T   2. F   3. F   4. F   5. T   6. T   7. T   8. F   9. T   10. F

Based on the issues discussed, the teacher together with the students formulates the lesson topic. He discusses with students the purpose of the lesson, the goals of the lesson and jointly draws up the evaluation criteria and notes that today in the lesson they will compare the intensity, potential, strength and work of the gravitational and electric fields.

Further, they jointly draw up a work plan.

1. Addition of a mental map.
2. Problem solving.

Cards with statements at the beginning of the lesson. docx

Middle

10 min

2 min

15 min

(Р)

Discussion of the augmented scheme between pairs.

Problem solving.

Evaluation Criteria:

- apply the similarity between the formulas to find the characteristics of the gravitational and vice versa electric fields.

1.       A stationary negatively charged sphere with a radius of 1 cm and a mass of 50 grams creates an electric and gravitational field in the surrounding space.

(a) Write down the direction of the field lines relative to the surface of the sphere.

(i) gravitational field ... perpendicular to the surface, the direction of the lines only to the surface ... ... ..

(ii) the electric field ... perpendicular to the surface, the direction of the lines can be either t of the surface or the surface of .................................................

(b) Calculate at a point remote from the center of the sphere at a distance of 20 cm. The sphere's charge is -4 µC.

(i) gravitational field strength .........................

(ii) electric field strength …………………………………

(c) Write down how the ratio of the intensity of the electric field to the intensity of the gravitational field changes as this distance increases by another 20 cm. Explain your answer.

........ will not change, since with a doubling of the distance, the intensity of the electric and gravitational fields will decrease by 4 times ........................... .................................... …………….

2.       Two protons are at a distance of 1 cm from each other. Calculate the ratio of the force of their Coulomb interaction to gravitational.Решение.

3*. Two horizontal metal plates are located at a distance of 1.8 cm from each other in a vacuum. The potential difference between them is 270 V, as shown in the figure.

The proton is in the space between the plates. Explain qualitatively and quantitatively why the gravitational field is not taken into account when a proton moves between the plates.

Answers:

1)        

2)       = 2,4 *10^-15 Н

Forces in an electric field far exceed the forces of gravity? Therefore, they can be neglected.

The reference scheme with the task. doc

Cards with tasks. docx

End

5 min

Reflection on the assessment of students' level of learning, using the table for students.

Student assignment Rate the level of achievement of the lesson criteria, using the notation “+” - I can do it without help, “±” - I need help, “-” - I can’t do it.

Attention! The second column is filled by the teacher according to the lesson results.

Homework: repeat the textbook, the material studied.

Solve the problem:

Problem source: https://easy-physic.ru/napryazhennost-polya-prostye-zadachi/

1. The intensity of the electric field created by the charge at a distance of 10 cm from it is 90 V / m. At what distance from the charge is the electric field intensity 30 V / m less?

2 *. Make a similar task for the gravitational field.

Differentiation - how do you plan to provide more support? What tasks do you plan to set for more capable students?

Grading - how do you plan to check students' level of learning?

Health & Safety

Support is planned through work in pairs with correct and incorrect statements and to supplement the reference scheme. During the discussion between the couples, they will be able to clarify the points they do not understand. When solving problems through mutual counseling and teacher support.

Through solving problems in the second half of the lesson.

Creating a favorable psychological atmosphere, the compliance of tasks to the level of preparedness of students, the change of activities, counseling.

What tasks do you plan to set for more capable students?

Оказание консультационной помощи учащимся, испытывающим затруднения

Students will:

Most students will:

Some learners will be:

- name one or two similarities between the gravitational and electrostatic fields;

- name one or two differences between the gravitational and electrostatic fields.

- list three or more similarities and differences, arguing your answer.

Lesson reflection

Use this section to reflect on the lesson. Answer the most important questions about your lesson from the left column.

Were the objectives of the lesson / learning objectives realistic?

Have all students reached the DH?

If not, why not?

Is the differentiation correct in the lesson?

Have the lesson temporal stages been sustained?

What were the deviations from the lesson plan and why?

Overall rating

What are two aspects of the lesson that went well (think about both teaching and learning)?

1:

2:

What could contribute to improving the lesson (think about both teaching and learning)?

1:

2:

What did I discover during the lesson about the class or the achievements / difficulties of individual students, what should I look for in the subsequent lessons?