"Quality" Quality and Density PPT Courseware 10

Description

"Quality" Quality and Density PPT Courseware 10

【Experience】Quality

Activity: Prepare a box of chalk and a piece of ice.

Activity 1: Move a box of chalk from one location to another.

Activity 2: Crush a piece of chalk into powder.

Activity 3: A piece of ice melts into water.

(1) How many substances are contained in a piece of chalk and a box of chalk ________(please fill in "the same" or "different"), _______ chalk contains a lot of substances.

(2) In activities 1, 2, and 3, the amount of matter contained in the object ________ (optional "yes" or "no") changes.

Tips: (1) Different one box (2) None

Doubtful about preview

1. What is the mass of an object? Why is mass said to be the basic property of an object?

2. Units of mass and unit conversion.

3. What are the common tools for measuring quality?

Explore 1 Quality

Consider the following questions based on the activities in “Experience”:

1. What are the similarities between a piece of chalk and a box of chalk? What are the differences?

Tip: A piece of chalk and a box of chalk are composed of the same substances. A box of chalk contains more substances than a box of chalk.

Reference answer: The similarity is that the types of substances are the same, but the difference is the amount of substances contained.

2. Hammers and nails are both made of iron. Hammers and nails are called objects in physics, and the material "iron" they are made of is called ______. The amount of this substance contained in a hammer and an iron nail in the picture is different. In physics, ______ is used to represent this difference.

Tip: Both hammers and nails are composed of the substance "iron". A hammer contains more iron than a nail. It can be seen that there are more and less substances that make up the object. In physics, mass is used to represent objects. The amount of substances contained.

Reference answer: Substance Quality

3. Think based on activities 1, 2, and 3: When the position, state, and shape of an object change, does the mass change? What conclusions can you draw from this?

Tip: If you move a box of chalk from one location to another, let a piece of ice melt into water, or crush the chalk into powder, the amount of matter contained in the object does not change, so the mass does not change. It can be seen that quality is a basic attribute of an object, which has nothing to do with changes in the state, shape, and spatial position of the object.

Reference answer: Quality remains unchanged. Quality is a basic attribute of an object, which has nothing to do with changes in the object's state, shape, or spatial location.

Explore 2 units of mass

1. Fill in: Can you write down the unit of mass of each object in the picture?

Reference answer: mg　g　kg　t

2. Try to complete the following unit conversions:

(1)50t=_________kg　60kg=_________mg

(2)24mg=_________g 56g=_________kg

Tips: (1)50t=50×103kg=5×104kg

60kg=60×106mg=6×107mg

(2)24mg=24×10-3g=2.4×10-2mg

56g=56×10-3kg=5.6×10-2kg

Reference answer: (1)5×104 | 6×107

(2)2.4×10-2　5.6×10-2

Knowledge summary

1. Mass: The object contains ___________, represented by the letter __.

2. Properties: Quality is a basic attribute of an object, and has nothing to do with the object’s _____, _____, and __________.

3.Unit:

(1) Basic unit: _____, symbol ___.

(2) Other units: tons (t), grams (g), milligrams (mg).

(3)Conversion relationship:

4. Commonly used tools for measuring quality: _________.

【Expansion】Electronic scale

Electronic scales are currently widely used weighing and pricing tools in stores and markets. Its biggest advantage is its ability to weigh and price automatically, quickly and accurately. In addition, it also has multiple functions such as accumulating the amount of different goods purchased by customers, accumulating the total amount, peeling and so on. The picture below shows the appearance of a general electronic scale. In the front three digital display windows, the left one shows the quality, the middle one shows the unit price of the product, and the right one shows the pricing. The device on the right is the command keyboard, and the flat scale above is where the products are placed.

Test Points Estimation of Quality

[Typical example] An object with a mass of 1.5×105mg may be ()

A. A cow B. An old hen

C. A book D. An elephant

[Idea Guide] Convert the mass unit mg in the question into the familiar unit kg.

【Exquisite analysis】Choose C. This question tests estimating the mass of an object. 1.5×105mg=1.5×102g=1.5×10-1kg=0.15kg. The mass of an adult cow should be between 500 and 1000kg, and even a calf weighs dozens of kilograms; the mass of an old hen is about 2kg; the mass of a book is close to the 0.15kg in the question; an elephant The mass should be several tons. So choose C.

[Method Summary] Methods for solving quality estimation problems

(1) Memorize the masses of some common objects: for example, a one-yuan coin is about 6g, an egg is about 50g, a middle school student is about 45kg, etc.

(2) Convert the mass unit of uncommon objects into common kg or g, and compare it with the mass of common objects to judge.

1. The mass of an object is determined by ()

A.The shape of the object B.The state of the object

C. The amount of material contained in the object D. The position of the object

[Analysis] Choose C. This question examines the concept of quality. The amount of matter contained in an object is called mass. The more matter an object contains, the greater its mass; the less matter it contains, the smaller its mass. Quality has nothing to do with the object's shape, state, and spatial location. So choose C.

2. (2012 Hulunbuir High School Entrance Examination) After ice melts into water, the mass will be ()

A. Become larger B. Become smaller C. Uncertain D. Remain unchanged

[Analysis] Choose D. This question tests the understanding of the concept of quality. Mass is a property of an object. Its size does not change with changes in the shape, state, and position of the object. When ice melts into water, its state changes, but its mass remains unchanged.

3. (2012 Taizhou High School Entrance Examination) Xiao Ming’s mother bought an old hen from the market and asked Xiao Ming to guess its quality. Which of the following values ​​do you think Xiao Ming’s guess should be close to to be realistic ()

A.20g B.200g C.2kg D.20kg

[Analysis] Choose C. This question examines the estimation of quality. The mass of an old hen is about 2kg.

4. Use a balance to weigh the mass of a plastic bottle, then move it to another location to measure its mass, then cut it into pieces and weigh it on the balance. Compare the three measurement results and find that the measurement values ​​are equal, which indicates the mass of the object. Nothing to do with.

[Analysis] This question examines the concept of quality. Mass is a fundamental property of objects. It does not change with the shape, state, or position of the object, so the same plastic bottle at two different positions has the same mass after being cut into pieces.

Answer: Position Shape

Keywords: Quality and density teaching courseware, quality teaching courseware, Shanghai Science Edition eighth grade physics PPT courseware download, eighth grade physics slide courseware download, quality and density PPT courseware download, quality PPT courseware download, .PPT format;

For more information about the "Mass and Density Quality" PPT courseware, please click the Quality and Density ppt quality ppt tag.

"The Relationship between Acceleration, Force and Mass" Newton's Laws of Motion PPT teaching courseware:

"The Relationship between Acceleration, Force and Mass" Newton's Laws of Motion PPT teaching courseware Part One: Laying the Foundation for Necessary Knowledge Literacy [Purpose of Experiment] 1. Explore the relationship between acceleration, force and mass. 2. Learn to use ________ method to explore the laws of physics. 【experiment equipment..

"The Relationship between Acceleration, Force and Mass" Newton's Laws of Motion PPT download:

"The Relationship between Acceleration, Force and Mass" Newton's Laws of Motion PPT Download Part One Content: [Discipline Literacy Objectives] Scientific Inquiry: 1. Learn to use the controlled variable method to study physical laws. 2. Master the method of using images to process data. 3. Explore acceleration, force, and mass..

"The Relationship between Acceleration, Force and Mass" Newton's Laws of Motion PPT courseware:

"The Relationship between Acceleration, Force and Mass" Newton's Laws of Motion PPT Courseware Part One: Experimental Basics Experiment Purpose 1. Explore the relationship between acceleration, force and mass. 2. Learn to use the control variable method to explore physical laws. Experimental equipment: wooden board with fixed pulley, thin...

File Info

Update Time: 2024-11-14

This template belongs to Physics courseware Shanghai Science Edition 8th Grade Physics industry PPT template

Preview