What is Length?

Transcript

Chapter 5 Class 6 Measurement of Length and Motion To find Quantity How long Movement Here we will learn about 2 things Length and Motion What is Length?It is a measurement of how long something is Example 1 Length of a cricket pitch Example 2 Length of a Laptop How to measure length of a Laptop? Option 1 We use handspan (Balisht) Problem Different people have different size of hands and they measure differently How to measure length of a Laptop? Option 2 We use scale to measure length Note Scale shows units in cm (Centimetre) Measurement will be same for all persons How to measure length of a Floor? Option 1 Using our foot Problem Different people have different size of foot so they measure differently How to measure length of a Floor? Option 2 Using Measuring Tape Note Measuring Tape shows measurement in centimetre (cm) Measurement will be same for all persons How do tailors measure length of a dress?Option 1 Angula (Finger Width) Problem Different people have different width of finger so they measure differently How do tailors measure length of a dress?Option 2 Use Measuring Tape to measure Benefits Measurement will be exact same for all persons It is a fixed standard quantity used to measure something What are Units of Measurement?Example Units of length is measured as follows TRADITIONAL Angula Dhanusa Yojana MODERN Centimetre Metre Kilometre Traditional Methods of MeasurementSMALL ANGULA (Finger Width) DHANUSHA (1 Dhanusha = 100 Angulas VERY LARGE YOJANA (1 Yojana = 1000 Dhanusha Modern Methods of MeasurementTINY Millimetre (mm) SMALL Centimetre 1 cm = 10 mm LARGE Metre 1 m = 100 cm VERY LARGE Kilometre 1 km = 1000 m Different Units of Measurement on a Scale Here, it shows cm and mm Here, it shows foot and inches This creates confusion Due to this we follow Standard Units What are Standard Units?It refers to International System of Units This is universally followed through out the world It is also called SI Units In this chapter, We will learn about only this Different SI Units What is SI Unit of length?It is measured in Metre Its symbol is m Example Length of Table = 1 m Or 3.28 ft This is Standard Unit This is not Standard Unit 1 m or 3.28 ft SummaryUniversally Followed Measurements This is Standard Unit m cm mm km These are linked to metre So also internationally used Not Universally Followed Foot Inches These are not followed internationally Note :- 1 foot = 12 inches = 30 cm