# NCERT Science Class 6 Chapter 10 Summary/revision notes

Science Class 6 Chapter 10 Motion and Measurement of Distances Summary/revision notes

We can measure distances in various ways like by hands, handspan, foot, etc. These measurements are not precise and vary from person to person. So we use a  standard convention which is accepted by everyone. It the Internation system of the unit (SI).

As per SI

1 meter equals to 100 centimeter or 1000 milimeter.

For larger distance we use kilometre.

One kilometre equals to 1000 meter.

### Motion and its type:

An object is said to be in motion if its place varies from time to time. On the basis of the movement a motion can be:

Rectilinear: Movement on a straight path.

Circular: Movement on a circular path. e.g. a moving fan.

Periodic motion: In this motion, an object repeats its place after some time. For example, movement of a swinging jhoola, pendulum, strings of guitar etc. are examples of periodic motion.

Combination of circular motion and rectilinear motion: In this type of motion object shows a circular motion as well a rectilinear motion. For example a rolling ball, a moving cycle wheel.