# NCERT Class 6 Science Chapter 10: Motion and Measurement of Distances YouTube Lecture Handouts

Watch video lecture on YouTube: NCERT Class 6 Science Chapter 10: Motion & Measurement of Distances NCERT Class 6 Science Chapter 10: Motion & Measurement of Distances

## What is Physics?

Properties of world around us

## Modes of Transport

• Man has invented faster and faster modes of transport

• From moving on foot to inventing wheels, using animals, petrol engines, and even rockets.

## Types of Modes of Transport

• Land Transport

• Corridors- Rails (track), roads (corridor)

• Unstructured- People and animals moving

• Water Transport

• Boats, streamers (present from long ago)

• Oceanic – Large intercontinental

• Inland Transport (rivers)

• Air Transport (1900)

Air, rocket etc.

## Fuel in Vehicles

Animal/human powered

Fossil

• Petrol

• Diesel

• Coal

• Renewable

Solar Cells

• Electro-magnetic

• Electric cars

• Levitating

• Hyperloop

• Ropeway

Electric locomotives (train engines)

## Speed of Transport

• Walking

• Bullock cart

• Cycling

• Motor Cycle/Cars

• Trains and bullet trains

• Airplane/helicopter (supersonic planes)

• Rockets/Spaceships

## What is Measurement?

• Comparing unknown to known.

• Always done using a measure (usually numerical) + unit for example 2 meters

## Units of Measurement

### Primitive Units Used Body Parts

Cubit (18 to 22 inches)

Fathom – Length of the outstretched arm (roughly 6 feet). Water depth is measured in fathoms.

Hand-span – Roughly 9 inches

• Thumb (basis of inch)- thumbnails

• Stride Length

Foot:

## Primitive Units Varied Across the World (Indian Distance Units Are Given Below)

Small length measurements used angul (finger) or a mutthi (fist). Measures of larger lengths are given below:

## So What is the Problem?

• Lilliput and Brobdingnag?

• Increasing trade, travel and globalization

## Some Unification

• MKS-System: Length is measured in Meter (M), mass is measured in Kilogram (K) and time is measured in Second (S). Developed in 1970 in France.

• CGS-System: In this system, length is measured in centimeter (C), mass in gram (G) and time in second (S).

• FPS-System: In this system, length is measured in foot (F), mass in pound (P) and time in second (S).

## SI Units

• Modern form of the metric system (from France)

• Seven base units (ampere, kelvin, second, metre, gram, candela, mole)

## What is a Meter?

Length of the path travelled by light in a vacuum during a time interval of 1/299,792,458 of a second.

## Important Prefixes

 Factor Prefix Symbol giga G mega M kilo k hecto h deka da deci d centi c milli m micro nano pico

## Other SI Units

 Symbol Name Quantity A ampere electric current K kelvin Temperature s second Time m metre length g gram mass cd candela luminous intensity mol mole amount of substance

# Measuring Devices and Right Measurement

How to measure circumference of the globe?

## Correct Way of Doing Measurement

Place the scale in contact with the object along the object

Use good part of the scale

Correct position of eye to reduce parallax

## Choosing Right Device

• Length to be measured

• Shape of the object

• Accuracy required

# Motion and Types of Motion

Motion is any kind of a change in the position of an object with time.

Some objects can move while others are stationary.

• Translatory: All particles of a body move through the same distance in the same time.

• Rectilinear

• Curvilinear

• Random

• Rotatory or Circular – has a center point

• Rolling- center point undergoes translatory motion

### Periodic or Non-Periodic

• Vibratory: Periodic motion due to elastic property of body. For example scale vibrating throughout the of body.

• Oscillation: Periodic but translational. For example, pendulum.

• Reciprocating: Moving saw back and forth

• Rotatory: Earth, sun etc.