Municipal state educational institution
"Vorotynskaya secondary school"
Subject:
«
MEASURING BODY VOLUME BY DIFFERENT METHODS»
Garusin Savely -
7th grade student
Leader:
Kozicheva E.N. - Physics teacher
2012 r.
EDUCATIONAL AND RESEARCH PROJECT
TOPIC: MEASURING BODY VOLUME IN DIFFERENT METHODS
ANNOTATION OF THE PROJECT
When studying physics in the 7th grade according to the textbook A.V. Peryshkina students perform laboratory work "Measurement of body volume".
The purpose of the work is to learn how to determine the volume of the body using a measuring cylinder.
However, there is no theoretical material in the textbook. In the course of work on the project, the missing knowledge was obtained from different sources (textbooks, encyclopedias, the Internet).
This work contains the definition of body volume as a physical quantity, historical facts determination of the volume of geometric bodies, units of measurement of volume in the present and in antiquity.
The experiments described in the work expand knowledge about the methods of measuring the volume of bodies. And they allow us to conclude that the volume of one and the same body can be measured in different ways. The research results are presented in the form of a presentation.
The materials collected in the work can be used to conduct a physics lesson in grade 7 "Measurements of body volume".
MOTIVATION
In physics class, we measured the volume of bodies. In mathematics lessons, they solved problems for calculating the volumes of cubes and parallelepipeds. I decided to learn about the methods of measuring the volume of the body, the units of measuring the volume now and in antiquity.
Objective of the project:
Study of ways to measure volume.
Project objectives:
Learn the history of measuring the volume of geometric bodies.
Get acquainted with the methods of measuring body volume.
Expand knowledge of volume units.
Make a presentation that can be used in a physics lesson in grade 7 on the topic "Measuring body volume"
BODY VOLUME CAN BE MEASURED IN DIFFERENT WAYS.
Research methods:
Collection of information on the research topic.
Experiment.
Analysis of the data obtained.
Physical quantity - VOLUME
Subject of study:
RESULTS OF THE STUDY
The history of measuring the volume of bodies
Volume - quantitative characteristics of the space occupied by a body or substance. The volume of the body or the capacity of the vessel is determined by its shape and linear dimensions. With the concept volume closely related concept capacity, that is, the volume of the inner space of a vessel, packing box, etc. The synonym for capacity is partially capacitybut in a word capacity also denote vessels.In ancient Egyptian papyri, in Babylonian cuneiform tablets, there are rules for determining the volume of a truncated pyramid, but no rules are given for calculating the volume of a complete pyramid. The ancient Greeks were able to determine the volume of a prism, pyramid, cylinder and cone even before Archimedes. And only he found a general method to determine any area or volume. Archimedes used his method to determine the area and volume of almost all bodies that were considered in ancient mathematics. He deduced that the volume of the sphere is two-thirds of the volume of the cylinder described around it. He considered this discovery to be his greatest achievement. Among the outstanding Greek scientists of the 5th - 4th centuries. BC who developed the theory of volumes were Democritus and Eudoxus of Cnidus.
According to Archimedes, even in the 5th BC. Democritus of Abdera established that the volume of a pyramid is equal to one third of the volume of a prism with the same base and the same height. Full proof this theorem was given by Eudoxus of Cnidus in IV BC.
The volumes of grain barns and other structures in the form of cubes, prisms and cylinders were calculated by the Egyptians and Babylonians, Chinese and Indians by multiplying the area of \u200b\u200bthe base by the height. V \u003d S Hwhere S \u003d a b Is the area of \u200b\u200bits base, and H- height. but the ancient East were known mainly only a few rules found empiricallywhich were used to find volumes for the areas of figures. At a later time, when geometry was formed as a science, a general approach was found for calculating the volumes of polyhedra.
Euclid does not use the term “volume”. For him, the term "cube", for example, means the volume of a cube. In the XI book of "Elements", among others, the following theorems are set forth.
Parallelepipeds with the same heights and equal bases of the same size.
The ratio of the volumes of two parallelepipeds with equal heights is equal to the ratio of the areas of their bases.
In equal-sized parallelepipeds, the areas of the bases are inversely proportional to the heights.
Volume units
Volume - This is the capacity of a geometric body, that is, a part of the space bounded by one or more closed surfaces. The capacity or capacity is expressed in the number of cubic units contained in the volume. With the selected unit of measurement, the volume of each body is expressed as a positive number, which shows how many units of measurement of volumes and parts of a unit are contained in this body. It is clear that the number expressing the volume of a body depends on the choice of the unit for measuring volumes, and therefore the unit for measuring volumes is indicated after this number.
c) I measure the volume of the spilled water using a beaker.
d) The volume of water is equal to the volume of the body. 
V \u003d 5cm 3
Findings:
The body is cylindrical
a) I measure the height of the cylinder h
b) I measure the diameter of the circle d
d \u003d 2.3cm
c) Using the formula, we calculate the area of \u200b\u200bthe base of the cylinder
d) Using the formula, we calculate the volume of the body
V \u003dSh
V \u003d 20.3 cm 3
2) Measure body volume with a beaker
a) I pour 150 cm 3 of water into a beaker.
b) I completely immerse my body in water. 
c) I determine the volume of water with a body immersed in it. d) The difference in water volumes before and after immersion of the measured body in it will be the volume of the body.
V = V2 – V1
e) I write down the measurement results in the table:
3) I measure the volume of the body using a casting vessel:
a) I fill the vessel with water up to the opening of the drain tube.
b) I completely immerse my body in it.
c) I measure the volume of the spilled water using a beaker.
d) The volume of water is equal to the volume of the body.
V \u003d19 cm 3
Findings:
In all experiments, the volume of the body was approximately the same.
Hence, the volume of the body can be calculated using any of the proposed methods.
RESULTS OF THE STUDY
The experiments carried out allow us to draw a conclusion. The hypothesis put forward in the research project was confirmed:
BODY VOLUME CAN BE MEASURED IN DIFFERENT WAYS.
A.V. Peryshkin Physics textbook for grade 7 - M .: Enlightenment, 2010.
Encyclopedic Dictionary of a Young Physicist / Comp. V.A. Chuyanov - M .: Pedagogy, 2004.
Physics experiment in high school: 7 - 8 cl. - M .: Education 2008.
Internet resources:
Wikipedia. Volume. ru.wikipedia.org/wiki/ Volume Unit Category
Volume measurement history http://uztest.ru/abstracts/?idabstract\u003d216487
Themes for presentations. http // aida.ucoz.ru
Geometric shape
Methodical instructions to laboratory work
Krasnoyarsk 2016
Measurement of body volumes
Correct geometric shape
Objective:
- calculate the volume solid correct geometric shape;
- learn how to process the measurement results and evaluate the accuracy of the measured value by means of errors.
Devices and accessories: cylindrical body, vernier caliper.
The main provisions of the theory of errors
Physics course forms the basis basic training engineer of any specialty. Since physics is an experimental science, the implementation of laboratory work in learning laboratories It is an integral part physical education student. Receiving experimental data in the process of conducting a physical experiment, the student must be able to process its results. Therefore, first of all, it is necessary to master the techniques and methods of calculating the errors of the measured quantities, since any physical quantity, as a result of the influence of many objective and subjective reasons, can be measured only approximately, with some accuracy.
This section describes a technique for processing measurement results, which is based on the science of measurements, methods and means of ensuring their unity and ways to achieve the required accuracy - metrology... Metrology based on results mathematical statistics, provides information on how to process the results of measurements of quantitative information about the properties of objects in the world around us with a given accuracy and reliability.
Direct and indirect measurements. Types of errors
The goal of any physical experiment is to measure physical quantitiesthat characterize the phenomenon under study. The result of a single measurement, often called an observation, is the numerical value of the measurand.
Measurement of quantity: the process of experimentally obtaining one or more quantity values \u200b\u200bthat can reasonably be attributed to a quantity. Measurement implies comparison of values \u200b\u200bor includes counting objects. The measured value can be correlated with another reference value, taken as a unit of measurement.
EXAMPLE Measurement of a block of length made by comparison with a reference block on a vernier caliper.
Measurement result of a physical quantity; measurement result; result: the value of a quantity obtained by measuring it.
According to the method of obtaining the result of measuring a physical quantity, direct, indirect and joint measurements are distinguished.
Direct measurement: measurement in which the desired quantity value is obtained directly from the measuring instrument.
Examples of
Measuring the length of a part with a micrometer.
Measuring current with an ammeter.
Confidence limits of measurement error
And the confidence level
Let us suppose that with repeated measurements of a physical quantity in an experiment, its values \u200b\u200bwere obtained. We assume that all measurements were performed with the same thoroughness and using the same technique. Our task is to find: the arithmetic mean of the measured value; confidence limits of the measurement result error at a given value of the confidence level.
As mentioned above, its arithmetic mean should be taken as the true value of the measured quantity. In this case, the value lies within some limits near. It is necessary to find this interval within which the value of the determined quantity can be found with a given probability. To do this, set a certain probability close to 1. Then determine for it the lower boundary of the interval and the upper boundary of the interval within which the value of the determined quantity should be located (see Fig. 1).
The interval here gives confidence bounds of error, determining the upper and lower bounds of the interval within which the value of the measured quantity is located with a given probability.
The probability is called confidence level.
Figure: 1 Explanation of terms
The final measurement result is written as
The above record should be understood as follows: there is a certain degree of confidence that the value of the measured quantity is within the calculated interval from to. The equality of the confidence level to the value means that when a large number of measurements are carried out, in 95% of cases (the results of measurements of a physical quantity, performed with the same care and on the same equipment, will fall within the confidence interval.
Note that for calculating the confidence limits of the error (without taking into account the sign), the confidence probability is taken equal to 0.95. However, in special cases, if it is not possible to repeat measurements under unchanged experimental conditions, or if the results of the experiment are related to human health, a confidence level of 0.99 is allowed.
EXAMPLE The result of measuring the cylinder diameter with a caliper is shown as
| . |
This entry implies that as a result of carrying out a certain number of measurements of the cylinder diameter, the arithmetic mean value of the quantity is mm. Confidence Limits of Error mm, and the measured value of the diameter lies in the range from before mm. This result corresponds to the confidence level ... The latter fact means that in 95% of cases the results of diameter measurements for any number of subsequent measurements with the same tool will be within the interval from before mm.
In the previous example, the measurement error was expressed in the same units as the measured value itself. This notation expresses the result in absolute terms.
Absolute error: error of measurement, expressed in the unit of the measured quantity.
However, the error can also be expressed in relative terms.
Relative error: measurement error, expressed as the ratio of the absolute error to the true value, which is taken as the arithmetic mean. The boundaries of the relative error in fractions or percentages are found from the ratios
EXAMPLE We use the previous example, the results of which were presented as: .
Here the confidence limits of the absolute error mm, and the relative error , or 0.26%.
And the measurement result
The issue of calculation accuracy is very important, as it avoids a lot of unnecessary work. It should be understood that it is not necessary to carry out calculations with an accuracy exceeding the limit that is ensured by the accuracy of determining the quantities directly measured in the experiment. After processing the measurements, the errors of individual results are often not counted and the error of the approximate value of the value is judged by indicating the number of correct significant digits in this number.
Significant figures an approximate number, all digits except zero are called, as well as zero in two cases:
- if zero is between significant digits.
EXAMPLE Number 2053 contains four significant digits;
- when zero is at the end of the number and it is known that the units of the corresponding category in this number not.
EXAMPLE 5.20 has three significant digits. It follows from this that the measurement took into account not only units, but also tenths and hundredths. There are only two significant digits in the number 5.2, therefore, only whole and tenths were taken into account.
Approximate calculations are made subject to the following rules:
– when adding and subtracting as a result, as many decimal places are stored as the number with the fewest decimal places contains.
Example - 0.8934 + 3.24 + 1.188 \u003d 5.3214 5,32.
– when multiplying and dividing as a result, as many significant digits are retained as the number with the least significant digits has.
Example - 8.632 2,8 3,53 = 85,318688 85,3.
If one of the factors starts with one, and the factor with the least number of digits starts with any other digit, then as a result one more digit is stored than in the number with the least significant number.
Example - 30.9 1,8364=56,74476 ≈ 56,74.
When calculating intermediate results, save one digit more than the above rules prescribe (one digit is left for "reserve"). In the final result, the figure left for the "stock" is discarded. To clarify the meaning of the last significant digit of the result, the digit following it should be calculated. If it is, it should simply be discarded, and if it turns out, then, when discarding it, the previous figure must be increased by one. Usually, one significant digit is left in the absolute error, and the measured value is rounded to the place in which the significant digit of the absolute error is located;
– when calculating the values \u200b\u200bof functions ,, for some approximate number, the result should contain as many significant digits as there are in the number.
Example - .
It should be noted that the absolute error is pre-calculated with no more than two significant figures, and in the final result, round off again to one significant digit. For a relative error, leave two significant numbers.
The basic rule for presenting results is that the value of any result must end with a digit in the same decimal place as the last significant digit of the error.
Example - Result with an error of 0.5, you need to round up to ... If the same result is obtained with an error of 5, then it is correctly represented as: ... And if the error is 50, then we write the result as .
Work order
1. Learn to use a measuring device - a caliper (Appendix A).
2. Measure the diameter of the cylinder at both ends with a vernier caliper. Carry out 5 measurements by turning the cylinder around its axis. Record the results in table 2.
3. Measure the height of the cylinder using a vernier caliper 5 times, turning the cylinder around its axis by a certain angle (about 45 °) before each measurement. Record the results in table 2.
4. Calculate the arithmetic mean values \u200b\u200bof the height and diameter of the cylinder using the formulas
 ,
|  .
|
table 2
Measurement and Calculation Results
| Measurement number | , mm | , mm | , mm | , mm | , mm | , mm |
| … | ||||||
| n | ||||||
7. Determine the value of the systematic error of the caliper (in our case, this permissible error of the measuring instrument) in the form 
... If and differ from the error of the measuring instrument by more than three times, then the largest of the values \u200b\u200band or is taken as the value of the measurement error. Otherwise, measurement errors are determined by the formulas:
in which the value is determined from relation (8), and for the height and for the diameter are calculated by the formula (7)
,
.
The value is found according to the expression, where instead of the systematic error, the error of the measuring instrument was substituted.
8. Calculate the relative error, expressed as a percentage, for measuring the height and diameter of the cylinder using the formulas
,
%.
If the constant is rounded up to 3.14, then 
- the error of such rounding. Formula (18) is obtained by taking the logarithm of expression (17), and then differentiating it according to the method of paragraph 1.5 for all variables, including a constant.
12. Record the final result as:
| , mm, P \u003d 0.95, \u003d…%, mm, P \u003d 0.95, \u003d…%, mm 3, P \u003d 0.95, \u003d…% |
4 Control questions and tasks
1. Give definitions and give examples: measurement of a quantity; measurement result; measurement result errors; the arithmetic mean of the measured value; direct measurement; indirect measurement; joint measurement; multiple measurements.
2. List and describe the types of errors and methods of obtaining the result.
3. How to determine the boundaries of the systematic error in the presence of less than three of its components?
4. Name the difference between the relative error and the absolute measurement error.
5. Draw conclusions of formulas (9), (10) and (18).
6. On what parameters does the value of the Student's coefficient depend?
8. Under what conditions can random or systematic errors be neglected?
10. Explain the meaning of the confidence limits of the absolute error, relative error and confidence level.
11. How is the final result of the measurements recorded?
Bibliographic list
1.GOST R 8.736-2011 State system ensuring the uniformity of measurements. Multiple direct measurements. Methods for processing measurement results. Basic provisions. - Introduction. 01.01.2013. - Moscow: Standartinform, 2013 .-- 20 p.
2. Granovsky, V. A. Methods of processing experimental data during measurements [Text] / V.А. Granovsky, T.N. Siraya. - L .: Energoatomizdat, 1990 .-- 288p.
3. Zaidel, AN Errors in measurements of physical quantities [Text] / AN Zaidel. - L .: Nauka, 1985 .-- 112s.
APPENDIX A
Examples of
1 In Figure 3 a, the readings of the caliper are: ... In Figure 3 b, the readings of the caliper are: .
2 In Figure 4 a, the readings of the caliper are: ... In Figure 4 b, the readings of the caliper are: .
Before using the caliper, you need to check its technical condition by visual inspection. The vernier caliper must not have skewed lips, corrosion and scratches on the working surfaces. With the jaws aligned, the zero stroke of the vernier must coincide with the zero stroke of the bar. If the technical malfunctions described above or the mismatch of the vernier zero stroke jaws with the zero stroke of the rod are found in the caliper, then it is not allowed to use it. A defective caliper must be replaced with another.
When taking measurements with a caliper, the following rules must be observed:
- press the jaws 3 of the caliper (Fig. 2) to the part tightly, but without much effort, without gaps and distortions;
- when measuring the outer diameter of the cylinder, make sure that the plane of frame 2 is perpendicular to the axis of the cylinder;
- when measuring cylindrical holes, jaws 4 should be positioned at diametrically opposite points of the holes. They can be found by the maximum readings on the caliper scale. In this case, the plane of the frame 2 should pass through the axis of the hole in order to prevent errors when measuring the cylindrical hole;
- when measuring the depth of the hole, set the bar 1 at its edge perpendicular to the surface of the product. Pull the depth gauge ruler all the way into the bottom using frame 2;
- fix the obtained size with a locking screw and determine the readings, as described above.
Correct measurement of body volumes
Geometric shape
Determine the volumes of liquids, solids (regular and irregular shapes) and gases.
: a measuring cylinder or beaker, a ruler, a vessel with water, an irregularly shaped body, a rectangular parallelepiped-shaped body, a small flask, a glass.
Theoretical information
For example, the volume of a body that has the shape rectangular parallelepiped (Fig. 2), is calculated by the formula:
V \u003d Idh, where I is body length; d - body width; h - body height.
Directions for work
Preparing for the experiment
1. Before you start measuring, remember:
a) how the scale division price of the measuring instrument is determined;
b) how to correctly take readings of the graduated cylinder;
c) what safety measures must be observed when working with a beaker.
2. Determine and record the scale divisions of the ruler and graduated cylinder.
Experiment
Enter the results of all measurements in the table immediately.
1. Measure the volume of an irregularly shaped body using a measuring cylinder.
2. Determine the volume of the body of the correct geometric shape.
3. Determine the volume of the body of the correct geometric shape using a ruler.
4. Measure the volume of air in the flask and other vessels on your table.
| Experience number | Vessel name | Liquid volume, cm 3 | Air volume, cm 3 |
| 1. | |||
| 2. | |||
| 3. |
Analysis of experimental results
1. Having analyzed different ways volume measurements, indicate:
a) which of the methods for determining the volume of a solid is more universal and why;
b) what factors influenced the accuracy of your results.
2. Make a conclusion in which indicate what exactly you have learned to measure and for what the skills learned in the work can be useful.
Additional task
Suggest ways to measure the volume of an irregularly shaped body if:
a) its volume is less than the division price of the measuring vessel that you have;
b) the body does not fit into the vessel that you have.
Physics. Grade 7: Textbook / F. Ya. Bozhinova, N. M. Kiryukhin, E. A. Kiryukhina. - X .: Ranok Publishing House, 2007. - 192 p .: ill.
Lesson content lesson outline and support frame lesson presentation interactive technologies accelerative teaching methods Practice tests, online testing tasks and exercises homework workshops and trainings questions for class discussions Illustrations video and audio materials photos, pictures graphics, tables, diagrams comics, parables, sayings, crosswords, anecdotes, jokes, quotes Supplements abstracts cheatsheets chips for the curious articles (MAN) literature basic and additional vocabulary of terms Improving textbooks and lessons correction of errors in the textbook; replacement of outdated knowledge with new ones For teachers only calendar plans learning programs guidelines Long-term planning section: 7.2 APsychological attitude to the lesson.
Warm up exercise "Who quickly?"
micro-goal: rallying students.
Expected Result:coordination of joint actions, distribution of roles in the group.
The teacher notes the importance of the acquired skills during the warm-up
Students should quickly, without words, construct the following shapes using all students:
square; triangle; rhombus;
Reflective discussion:
Teacher question: Was it difficult to complete the task?
What helped with its implementation?
Actualization of knowledge of the formula for calculating the volume of a solid.
Strategy "Remember". From the course of mathematics, they recall how the volume of regular bodies was determined. Fill in the I KNOW column of the ZXU table.
Division into 3 groups with the help of signal cards. (red, green, yellow). Students choose cards from a closed basket.
Task 1. Determination of the volume of the body of the correct shape.
Descriptors:
Measures with a ruler the length, width, height of a matchbox.
Calculate the box volume by the formula ( V \u003d a × b × c).
Evaluating FO emoticons.
Goal message and lesson assessment criteria
FD feedback by the method "Comparison". The students demonstrate their beaker, name the division value and determine the volume of an irregularly shaped body.
Evaluation criterion
Determines the graduation price of the beakerMeasures liquid volume
Measures body volume
Task 3. Using a casting vessel, measure the volume of the body.
1 piece of glass
2. A piece of iron
3.A piece of porcelain
Descriptors:
1. Determines the graduation price of the beaker.
2. Pours water into the pouring vessel and lowers the measured body into the liquid.
3. Measures the volume of the poured liquid, determines the volume of the body.
PO feedback ... Students receive candy for this activity.
Fill in the LEARNED column of the ZXU table.
Beakers, vessels of different sizes, bodies of irregular shape (stones, pieces of plasticine, a glass of water,
potatoes or other vegetables and fruits)
Ebb vessel, beaker with water.
End of the lesson
Reflection. Teacher, today, using a beaker, we determined the volume of the body of the correct and irregular shape. Fill in I WANT TO KNOW table ZXU.
ZXU table
I knowI want to know
Learned
homework: Measuring the volume of bodies of regular and irregular shape
Posters, markers, cards
Differentiation - in what way would you like to provide more support? What assignments do you give students who are more capable than others?
Assessment - how do you plan to check the students' level of assimilation?
Health and safety
1. Task 1 for repetition determination of the volume of the box. Division into groups.
2. Task 2Measure body volume with a beaker.
3. Task 3 Measure the volume of irregular bodies using a casting vessel.
Differentiation can include the development of teaching materials and resources, taking into account the individual abilities of students, selection of assignments, expected results, personal support of students, (according to Gardner's theory of multiple intelligences).
By using time effectively, you can use differentiation at any stage of the lesson.
1.FD feedback using emoticons.
In this section, students experimentally recalled from a mathematics course how they measured the volume of a body of the correct shape (a box of matches).
2.FO feedback on the "Comparison" method. The students demonstrate their beaker, name the division value and determine the volume of an irregularly shaped body. Get asterisks.
3. The descriptors are used for self-assessment and receive a piece of candy.
Health-saving technologies.
Use of warm-up exercises in the classroom and active types of work.
Clauses of the Rules safety precautions,used on this lesson.
Reflection on the lesson
Was the lesson goal or learning goals realistic and accessible?
Have all students achieved the learning goal? If the students haven't reached the goal yet, why do you think? Did you differentiate correctly in the lesson?
Did you use your time effectively during the steps of the lesson? Were there any deviations from the lesson plan, and why?
Use this section of the lesson for reflection. Answer the questions that are relevant in this column.
Final grade
What two things went really well (take both teaching and learning into account)?
What two things could improve your lesson (take both teaching and learning into account)?
What new have I learned from this lesson about my class or individual students that I can use when planning my next lesson?
Make sure your body is waterproof as this method involves submerging your body in water. If the body is hollow or water can penetrate into it, then you cannot accurately determine its volume using this method. If the body absorbs water, make sure the water will not damage it. Do not immerse electrical or electronic objects in water as this may result in injury. electric shock and / or damage to the item itself.
- If possible, seal the body in a waterproof plastic bag (after letting it air out). In this case, you will calculate a fairly accurate value for the volume of the body, since the volume of the plastic bag is likely to be small (compared to the volume of the body).
Find the container that holds the body you are calculating. If you are measuring the volume of a small object, use a graduated volumetric beaker (scale). Otherwise, find a container whose volume can be easily calculated, for example, a container in the form of a rectangular parallelepiped, a cube, or a cylinder (a glass can also be thought of as a cylindrical container).
- Take a dry towel to place the body pulled out of the water on it.
Fill the container with water so that you can completely submerge your body, but leave enough space between the surface of the water and the top of the container. If the base of the body has irregular shapeeg rounded bottom corners, fill the container so that the water surface reaches a part of the body with a regular shape, for example, straight rectangular walls.
Mark the water level. If the water container is clear, mark the level on the outside of the container with a waterproof marker. If not, mark the water level on the inside of the container using colored adhesive tape.
- If you are using a measuring cup, you do not need to mark anything. Just write down the water level according to the graduation (scale) on the glass.
Submerge your body completely in water. If it absorbs water, wait at least thirty seconds and then pull the body out of the water. The water level should drop as some of the water is in the body. Remove marks (marker or adhesive tape) about the previous water level and mark new level... Then submerge the body in water again and leave it there.
If the body is floating, attach a heavy object to it (as a sinker) and continue calculating with it. After that, repeat the calculations exclusively with the sinker to find its volume. Then subtract the lead volume from the body volume with the weight attached to find the body volume.
- When calculating the volume of the lead, attach to it what you used to attach the lead to the body in question (for example, tape or pins).
Mark the water level with your body immersed in it. If you are using a measuring cup, record the water level according to the scale on the glass. Now you can pull the body out of the water.
The change in the volume of water is equal to the volume of an irregularly shaped body. The method for measuring the volume of a body using a container with water is based on the fact that when a body is immersed in a liquid, the volume of a liquid with a body immersed in it increases by the amount of the volume of the body (that is, the body displaces a volume of water equal to the volume of this body). Depending on the shape of the container with water used, there are different ways to calculate the volume of displaced water, which is equal to the volume of the body.
If you used a measuring cup, then you have recorded two values \u200b\u200bof the water level (its volume). In this case, subtract the volume of water before the body is immersed from the volume of water with the body immersed in it. You will get body volume.
If you used a box in the shape of a rectangular parallelepiped, measure the distance between the two marks (water level before body immersion and water level after body submersion), as well as the length and width of the water container. Find the volume of displaced water by multiplying the length and width of the container, as well as the distance between the two marks (that is, you calculate the volume of a small rectangular parallelepiped). You will get body volume.
- Do not measure the height of the water container. Measure only the distance between the two marks.
- Use