"Experiment: Explore the synthesis law of two forces at an angle to each other" Interaction - Force PPT

Description

"Experiment: Explore the synthesis law of two forces at an angle to each other" Interaction - Force PPT

Part One: Experimental Basics

Purpose

1. Practice using diagrams to find the resultant of two forces.

2. Verify the parallelogram rule for the result of two forces at an angle to each other.

Experimental principle

1. Determination of the resultant force F′: stretch the same rubber strip fixed at one end to a certain point, using only one force F′ at one time, and the joint action of two common point forces F1 and F2 at another time, then F′ is F1 And the combined force of F2.

2. Determination of the theoretical value F of the resultant force: Draw diagrams of F1 and F2, and use the drawing method to obtain the resultant force F according to the parallelogram rule.

3. Verification of the parallelogram rule: Within the allowable range of experimental error, compare whether F′ and F are equal in size and direction.

experiment equipment

Square wooden boards, white paper, two spring dynamometers, rubber strips, string sets, triangle plates, scales, and several thumbtacks.

Experimental procedures and data processing

1. Use thumbtacks to nail the white paper to the square board on the horizontal tabletop.

2. Fix one end of the rubber strip at point A with a thumbtack, and tie two string sets to the other end of the rubber strip.

3. Use two spring dynamometers to hook the string sleeves respectively, and pull the rubber strip at an angle to each other, so that the node of the rubber strip is pulled to a certain position O, as shown in Figure A. Record the readings of the two spring dynamometers, and use a pencil to trace the position of point O and the direction of the two string sets at this time.

4. Use a pencil and a scale to draw a straight line from point O in the direction of the two string sets. Draw a diagram of the readings F1 and F2 of the two spring dynamometers according to the selected scale, with F1 and F2 as adjacent sides. Use a scale to draw a parallelogram, and draw the diagonal line of the parallelogram through point O. This diagonal line is the diagram of the resultant force F, as shown in Figure B.

5. Use only a spring dynamometer to pull the knot of the rubber strip to the same position O through the string sleeve. Note the reading of the spring dynamometer and the direction of the string sleeve. Use a scale to press the same scale from point O. Draw a graph of the tension F′ of this spring dynamometer along the direction of recording, as shown in Figure B.

6． Compare whether the force F′ and the resultant force F obtained using the parallelogram rule are the same in magnitude and direction.

7. Change the size and angle of the two forces F1 and F2, and repeat the experiment twice.

Error Analysis

1. During use, there is friction between the spring and the casing of the spring dynamometer, between the pointer and the casing, or between the casing and the white paper of the spring dynamometer, which will cause system errors.

2. When measuring the tension twice, the knot of the rubber strip cannot be completely pulled to the same point, which may cause accidental errors.

3. If the angle between the two force components is too small or too large, and the values ​​of F1 and F2 are too small, accidental errors will occur when drawing using the parallelogram rule.

Experiment to explore the synthesis law of two forces at an angle to each other PPT, the second part of the content: Experimental test points

Test Point 1 Experimental Principles and Operations

Typical Example 1 , OB and OC are strings, and Figure B is a diagram drawn on white paper according to the experimental requirements.

(1) The meaning of "equivalent substitution" in this experiment is ________.

A. Rubber strips can be replaced with string

B． The effect of the spring dynamometer on the left can replace the effect of the spring dynamometer on the right

C． The effect of the spring dynamometer on the right can replace the effect of the spring dynamometer on the left

D． The effect of two spring dynamometers acting together can be replaced by the effect of one spring dynamometer.

(2) Among the two forces F and F′ in Figure B, the one whose direction must be along the AO direction is ________.

(3)[Multiple Choice]Among the following measures, the one that can reduce the experimental error is ________.

A. The string used to pull the rubber strip should be thinner and of appropriate length.

B． When pulling the rubber strip, the spring force gauge, rubber strip, and string should be close to the board and parallel to the board surface.

C． When recording the direction of tension on the spring dynamometer, the two points marking the same direction of the string should be further apart.

D． The angle between the pulling forces F1 and F2 should be 90°

[Analysis](1) The meaning of "equivalent substitution" in this experiment is that the effect of two spring dynamometers can be replaced by the effect of one spring dynamometer, so D is correct.

(2) F in question B is the theoretical value of the resultant force, and F′ is the actual value of the resultant force. Among the two forces, F′ must be directed along the AO direction.

(3) The string used to pull the rubber strip should be thinner and of appropriate length to determine the direction of the force. Option A is correct; when pulling the rubber strip, the spring dynamometer, rubber strip, and string should be close to the board and parallel to the board surface. Option A B is correct; when recording the tension direction of the spring dynamometer, the two points marking the same string direction should be farther apart, which can reduce the error when recording the direction. Option C is correct; the angle between the tension forces F1 and F2 is not necessarily 90 °, the size is appropriate, option D is wrong.

[Point-to-point training]

1. When doing the experiment of "exploring the law of the synthesis of two forces at an angle to each other":

(1) The following equipment must be used ________(multiple choices).

(2) When doing the above experiment, place a piece of white paper on a horizontal wooden board, fix one end of the rubber strip on the board, tie two string sets on the other end, and use two string sets at an angle to each other through the strings Use the spring dynamometer to pull the rubber strip to move the node to a certain position O. At this time, you need to write down: ①______________; ②______________;

③______________. Then use a spring dynamometer to stretch the rubber strip until the node reaches ______________, and then record ______________.

(3) In a certain experiment, the experimental results of a certain student are as shown in the figure, where A is the thumbtack that fixes the rubber strip, and O is the position of the node between the rubber strip and the string. In the figure, ________ is the theoretical value of the resultant force of forces F1 and F2; ________ is the experimental value of the resultant force of forces F1 and F2. Verify the parallelogram rule by comparing F and F′.

Analysis: (1) In the experiment, a parallelogram needs to be made, so a scale is needed, and the rubber strip needs to be stretched by a spring dynamometer to show the effect of force.

(2) During the experiment, the position of point O after the rubber strip is stretched, the reading of the spring dynamometer and the direction of the force should be recorded.

(3) The theoretical value of the resultant force in this experiment is obtained by making a parallelogram, while the experimental value of the resultant force is directly measured by using a spring dynamometer to pull the rubber strip so that the node reaches the same point O.

Test Point 2 Data Processing and Error Analysis

[Typical Example 2]In the experiment of "Exploring the synthesis law of two forces at an angle to each other", there are wooden boards, white paper, thumbtacks, rubber strips, string sets and a spring dynamometer.

(1) To complete the experiment, a student found another spring and measured its stiffness coefficient. The experimental data obtained are as shown in the table.

(2) In a certain experiment, the pointer position of the spring dynamometer is as shown in the figure, and its reading is ________N; at the same time, using the results in (1), the elastic force value on the spring is 2.50 N. Please draw these two common The resultant force of point forces is F.

(3) From the figure, we get F+=________N.

Keywords: PPT courseware for high school physics compulsory course 1 from the People's Education Press is free to download, experimental exploration of the synthesis law of two mutually angled forces PPT download, interaction force PPT download, .PPT format;

For more information about the PPT courseware "Experimental exploration of the synthesis law of two forces at an angle to each other and interaction force", please click the Experimental exploration of the synthesis law of two forces at an angle to each other PPT interaction force PPT tag.

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Update Time: 2024-10-18

This template belongs to Physics courseware People's Education Press High School Physics Compulsory Course 1 industry PPT template

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