Physical Quantity Length

 Fundamental Quantity – Length

Length is a measure of distance. In the International System of Quantities, length is a quantity with dimension distance. In most systems of measurement a base unit (Fundamental Unit) for length is chosen, from which all other units are derived.

In the International System of Units (SI) system the base unit for length is the metre.

Q. How 1 metre is defined?

Ans: Since 1983, the metre has been internationally defined as the length of the path travelled by light in vacuum during a time interval of  1/299 792 458 of a second by using a light source of known and stable wavelength.

Length is the measure of one spatial dimension, whereas area is a measure of two dimensions (length squared) and volume is a measure of three dimensions (length cubed).

Various terms for the length of a fixed object are used, and these include height, width or breadth and depth.

 

 

Measuring Devices:-

Vernier Caliper
To know more about vernier callipers 

Ruler

Screw Gauge 

Learning Beyond:

About Light Year

Often we get confused with the term ‘Light Year’

We often relate Year with time like One Year = 365 days= 8,764 hrs. = 5, 25,840 minutes

So thought comes in our mind that Light Year is use as a unit of time.

But that is not the case.

Light Year is a unit to measure very large celestial distance

1 Light Year = Equivalent to distance that light travels in one year with a speed of approx. 30, 00, 00,000 m/s

And that nearly equals 1 Light year=9.4607 × 10¹² km, and it’s enormous!

Because of its enormous value, its use to define the distances of astronomical bodies.

Some Examples:

The Nearest Star to our Solar System: Proxima Centauri

Distance: 4.26 Light Year

Farthest Object till date: Galaxy GN-z11

Distance: 13.4 Billion Light Year

GN-z11 superimposed image

 

 

Here's some PDF for better understanding:-

1. Mind Map for length:- Rainbow mind map of length
2.  Conversion:- Learn To Convert

 Here's some Google Forms to fill up:-

1. Quiz:- Quizzo
2. Students Corner:- Students work

 

Students Work:-

Abhilasha Jha, Jamshedpur

                                 

Sanvi Mishra, Amritsar

Arpita Mishra, Jamshedpur

Arpita Mishra, Jamshedpur

AUTHOR

RITU

LINK TO OUR OLD BLOGS:-

1)    Physical Quantities ✅ on 16^th Sept’ 2021

2)    Fundamental Quantity - Mass ✅  on 18^th Sept’ 2021

3)   Physical Quantity – Weight ✅  on 22^nd Sept’2021