# PSEB 6th Class Science Notes Chapter 10 Motion and Measurement of Distances

This PSEB 6th Class Science Notes Chapter 10 Motion and Measurement of Distances will help you in revision during exams.

## PSEB 6th Class Science Notes Chapter 10 Motion and Measurement of Distances

→ Measurement is a comparison of an unknown quantity with a known fixed quantity of the same kind.

→ Different modes of transport are used to move from one place to another.

→ Earlier cubit, hand span, or foot were used to measure the lengths or distances. Measurements made with them were not accurate.

→ The system of units used is known as the International System of Unit (S.I. Units) and is accepted all over the world.

→ The S.I. unit of length is meter.

→ Change in the position of an object with respect to things in the surroundings is called motion.

→ The motion of an object in a straight line is called linear motion.

→ In a circular motion, the object moves in a circular path and its distance from a fixed point (centre) always remains the same.

→ A motion that repeats itself after a fixed interval of time is called Periodic motion.

→ The fixed amount of known quantity is called unit.

→ The standard unit of length is a meter.

→ Distance: It is a measurement of length between two points.

→ Measurement: The comparison of an unknown quantity with some known quantity of the same kind.

→ Unit: The known fixed quantity taken as standard for comparison.

→ Odometer: A device fitted in motor vehicles to measure the distance covered by the vehicle.

→ Motion: When an object changes its position as compared to the surroundings with the passage of time, then the object is said to be in motion.

→ Linear Motion: The motion of an object in a straight line.

→ Circular motion: The motion of an object in a circular path, is called circular motion.

→ Periodic motion: When an object repeats its motions after a fixed interval of time, its motion is called periodic motion.