Grade 7 Measurement and Density · PDF fileGrade 7 Unit P.1 - Measurement & Density - 4 - Worksheet Q1: Here is a list of instruments used for measuring length: لوطلا سايقل

Grade 7 Unit P.1 - Measurement & Density

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Grade 7

Measurement

and Density


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Curriculum standards: 17.1, 17.2

Objectives

1-Know how to measure length and calculate area of

regular objects. كفخ قبش انطىل وحسبة انسبحخ نألجسبو انتظخ

2-Express large and small units using appropriate prefixes.

.انتؼجر ػ انىحذاد انكجرح وانصغرح ثبستخذاو انجىادئ انبسجخ

KEY WORDS انؼى

Meter انتر

Unit وحذح

Area يسبحخ

Measuring is an important part of science.

The metric system is an important part of

science.

SI unit: Means system international. It is

the modern form of the metric system. It

is based on the units of ten. و وحذاد ي انظبو انؼبن هى شكم حذث نهظبو انتري وستخذ

.10يضبػفبد

Prefixes are used to change the size of a

unit. انجىادئ تستخذو نتغر حجى انىحذح.

The three basic quantities we

have to measure in physics are

length, mass, and time.

How do you measure


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length?

Length is measured in a unit called the Metre (M).

انتر هى وحذح قبش انطىل األسبسخ

Rulers are used for measuring length. The ruler shows only centimeters &

millimeters not meters

To measure large lengths you can

use a metre ruler or a measuring

tape or trundle wheel.

To measure small lengths you can use

micrometer.

How do you calculate Area?

Area of a rectangle= length x Width

Area is measured in square units, such as square meters (m2).

انؼرض Xانطىل = يسبحخ انستطم

انسبحخ تقبش ثبنىحذاد انرثؼخ يثم انتر انرثغ

Calculate the area of the following

rectangle. احسة ساحح استط١ اتا

…………………………………………………………………………

………………………………………………………………………….

Metre ruler Measuring tape

Trundle wheel

Micrometre

Ruler


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Worksheet

Q1: Here is a list of instruments used for measuring length:

لديك مجموعة من األدوات لقياس الطول

Which would you use to measure the following distances?

أي األدواخ عىف تغتخذو نقياط انغافاخ انتانيح؟

The distance traveled by a snail in 5 minutes?

انغافح انتي يقطعها انحهضو في خظ دقائق

…………………………………………………………

The diameter of a wire? قطش عهك

…………………………………………………………

The circumference of the school ground? يحيظ عاحح انذسعح

…………………………………………………………

Your height طىنك

……………………………………………………………

The width of a paper. عشض وسقح

…………………………………………………………

How far you can run in 10 seconds. ؟ ثىا 10انغافح انتي تقطعها في تثهػ كى

……………………………………………………………

Meter ruler calibrated in millimeter divisions.

30 cm ruler calibrated in 0.5mm division.

50 m tape measure.

Micrometer screw gauge. Trundle wheel.

Micrometer

Trundle wheel


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Q2: Choose the correct answer for the following: :اختر االجبثخ انصححخ

1. The basic unit of length in the metric system is the

......وحذج قياط انطىل هي

A. yard. B. liter. c. gram. d. meter.

2-Area is determined by multiplying length by

........حذد تضشب انطىل في انغاحح خت

a. mass. b. temperature. c. width. d. volume.


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Curriculum Standards: 17.1

Objective:

1-Know how to calculate volume of regular and irregular solids, and

liquids, and gases. . كفخ حسبة انحجى نهىاد انصهجخ انتظخ وغر انتظخ وانسبئهخ وانغبزخ

KEY WORDS انؼى

Liter انهتر

Meniscus نسطح انقؼرا

Length انطىل

Width انؼرض

Liter: the basic metric unit for volume.

.حذج ام١اط األساس١ح حج:اتش

Meniscus: the curved surface of a liquid in a

graduated cylinder احاء سطح اسائ ف : اسطح امعش سائ

.اخثاس اذسج

Volume: the amount of space something takes up. .اجس شغمذاس اح١ض از : احج

Calculating Volume


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1- Measuring the volume of liquids: حجىو انسىائم

A graduated cylinder is used to measure the volume of a

liquid. A graduated cylinder is a glass or plastic container

that is marked with divisions. When a liquid is poured

into a graduated cylinder, the surface of the liquid is

curved. This curve is called the meniscus. اسائ حجاخثاس اذسج م١اط ٠ستخذ

اسائ ف١ مس عذج ألسا عذ ضع عثاسج ع أثب صجاج اخثاس اذسج

.٠صثح سطح اسائ ح زا االحاء ٠س اسطح امعش

To read the volume of a liquid, the surface of the liquid

should be at your eye level. You should read the mark on

the graduated cylinder closest to the bottom of the

meniscus. اسائ ٠جة ا ٠ى تى اع١ا ف ست سطح اسائ ا مشأ اعالح مشاءج حج

األلشب ماع اسطح امعش سائ

2- Volume of regular solids:

The volume of a solid can be measured in cubic centimeters. تماط تحذج حج ااد اصثح است١تش اىعة

You can find the volume of a cube or a rectangular prism by

multiplying its length by its width by its height.

V= H X L X W

انطىل xانؼرض xاالرتفبع =حجى انستطم

Calculate the volume of the

rectangular اجذ احج

V= H X L X W

V= 5 X 2 X 3 = 30 cm3

Calculate the volume of the

rectangular

……………………………………………………………

……………………………………………………………

Measuring

cylinder


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3- Volume of irregular solids: حجى انىاد انصهجخ غر انتظخ

To measure the volume of irregular solids we can use a graduated

cylinder.

1. Pour water into a graduated cylinder.

2. Measure the volume of the water (V1)

3. Put the rock irregular object in the water.

4. Then you read the volume of the water again (V2).

5. The volume of the object is found; and forms the following

equation:

The volume of the object = V2-V1

Volume of the rock =V2-V1

Volume of the rock =40mL-30mL

= 10 ml

=10 cm3

Worksheet

Q1:Choose the correct answer in the following statements:

:جبثخ انصححخ نكم يب هاختر اإل

1-A measure of how much space something takes up is

:جغى يا هى شغههيقياط انفشاغ انزي ي

a. mass. b. length. c. temperature. d. volume.

2-A graduated cylinder is used to measure

:انخثاس انذسج يغتخذو نقياط

a. mass. b. volume. c. length. d. temperature.


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3- To find the area of a rectangle you have to:

: يجة نقياط يغاحح انغتطيم

a. length length. b. length width.

c. square the width. d. length width x height

4- Volume can be measured in :يك قياط انحجى تىحذج

a. cm3. b. grams. c. liters. d. meters

Q2: Complete the following: كم يب ه أ

1. There are…………milliliters in one liter.

2. You can find the volume of a rectangular prism by multiplying its

length by its width by it’s…………..

3. One cubic centimeter is the same as …….milliliter.

4. 25CM is equal to………… ml

5. 10CM is equal to………….ml

6. ………….is used to measure the volume of a liquid.

7. The basic unit of volume in the metric system is………………

Q3: Calculate the volume of the box in the diagram.

:حجى انصذوق انج ف انشكماحست

…………………………………………………………………

1cm

2cm

4 cm


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Curriculum standards: 17.3

Objectives:

1- Define density.تؼرف انكثبفخ

2- Know how to calculate the density of liquids, gases, and regular

and irregular solids. .انغبزاد وانىاد انصهجخ انتظخ وغر انتظخ, كفخ حسبة انكثبفخ نهسىائم

KEY WORDS انؼى

Density انكثبفخ

Mass انكتهخ

Volume انحجى

Geologists need to measure the density of rocks. It helps them to

Identify the kind of rocks, and where it comes from. اصخس أ٠٠ذ أاع دزا ٠ساعذ ع تح. عاء دساسح األسض ٠حتاج ل١اط وثافح اصخس

.تأت To measure density we use the formula:

Density =mass/volume انحجى \انكتهخ = انكثبفخ

How

do

you


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find the density of gases (air)?

Air is mixture of gases. To find the density of the air, follow the

following steps:

1. Find the mass of a closed flask using the balance m1 اجذ وتح دسق فاسغ

2. Remove the air from the flask by a vacuum pump. افشغ اذسق ااء

3. Find the mass the empty flask m2 اجذ وتح اذسق فاسغ ااء

4. Calculate the mass of the air inside the flask

The mass of the air = m1 – m2 احسة وتح ااء از تذاخ اذسق

5. To find the volume of the air is found by opening the clip under

water so that water enters to replace the vacuum. Then pour the

water into a measuring cylinder to find the volume. ال٠جاد حج ااء استثذي ااء اضاي اذسق تااء ث احذ حج ااء تاستخذا اخثاس

اذسج

6. Use the formula:

Density= mass/volume

How to find density of water?

1. Find the mass of a dry empty beaker using a balance. اجذ

تاستخذا ا١ضا اجاف وتح اىأط

2. Use a measuring cylinder to pour exactly 100 ml (1 cm3) of

water into the beaker. ااء ف اىأط 100ضع

3. Now find the mass of the beaker with the water in it. اجذ وتح ااء اىأط عا

4. Work out the mass of the water from the results of steps

1 and 3. اجذ وتح ااء

5. Use the formula: density = Mass/volume


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How to find the density of irregular solid?

ن . األجسبو انصهجخ غر انتظخ حكثبفد ووج كف

We can calculate the density of a stone.

1. Find the mass of the rock using a balance.

2. Find the volume of the solid by using a

measuring cylinder and water.

3. Use the formula: density = Mass/volume

ك حسبة كثبفخ حصى ثقبش كتهخ انحصى ثبستخذاو انسا وحسبة انحجى

انحجى \انكتهخ= انكثبفخ: ثبستخذاو انخجبر انذرو وي ثى استخذاو انؼبدنخ

Worksheet

Q1:Choose the correct answer:

1. The density rule is: لا اىثافح

A-mass/volume b-volume/mass

c-mass/weight d-volume×length

2. What is the unit of density? ا حذج اىثافح

a- g/kg b-g/cm3 c-g / km3 d-m/cm

Q2: Define density? يب ه انكثبفخ

…………………………………………………………………………………………………………………………………

Q3: Calculate the density of a metal block that has a mass of

750g and a volume of 55 cm3?

سى 55غى وحجى 750يب ه كثبفخ قطؼخ يؼذخ نهب كتهخ 3

؟

…………………………………………………………………………………………………………………………………

……………………………………………………………………………………………………………………………….


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Q4: Use the diagram to answer the questions below.

:استخذو انشكم نإلجبثخ ػ األسئهخ انتبنخ a-What is the volume of the bar? ا حج امطعح

………………………………………………………………………………

..…………………………………………………………………………..

b- If the bar has a mass of 5 grams, what is its

density? وثافتا؟ غ ا 5إرا وات وتتا

…………………………………………………………………………………………………………………………………

………………………………………………………………………………………………………………………………..

When you walk at the seaside, do you feel lighter or heavier?

……………………………………؟ثم صاا أ أخف أش ع شاطئ اثحش تشعش تأه عذا ت

If you walk in deep enough, your feet come off the ground and you

start to float. This is because of upthrust.

عك تشتفع لذان ع اماع تثذأ تاطف ره تسثة لج دفع ااءأرا ش١ت ف ١ا إ

20cm


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Experiment:

1- Hang an object in a spring balance and measure its weight

ص ع١عك جس ت١ضا صثشو

W1 = …………………..

2- Lower the object into a beaker of water and measure its weigh

again. ضع اجس ف وأط ت اء ص شج اخش ع١

W2 = …………………..

The weight of the object in water is………………..……

.........................= وص انجغى في اناء

Why? ؟نارا

Because of ……………………………………………

Upthrust = W1 – W2

The weight of an object is less in water

because of the upthrust.

The difference between the two readings is

equal to the upthrus. انفرق ث انقرائت هى قىح انذفغ

If the weight of a rock is 2000 N. When you place the rock in water

the weight will be 1200N

١ت 1200ااء اصثح صا ١ت، عذ ضعا ف 2000ارا وا ص صخشج

1. Calculate the upthrust? احسة لج اذفع

.................................................................................................

……………………………………………………………………………………………..

2. Why the weight of the rock is less in water? ارا ص اجس أل ف ااء؟

.............................................................................................................

Documents

Grade 7 Measurement and Density · PDF fileGrade 7 Unit P.1 - Measurement & Density - 4 - Worksheet Q1: Here is a list of instruments used for measuring length: لوطلا سايقل