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Show on a big screenA bus leaves a stop. A minute later the bus is far away. How do you say clearly what happened?
This is Chapter 4 of your Class 9 book, Exploration. It is called Describing Motion Around Us. Numbers and graphs will do the describing.
What you will learn
- Where it is — position from a reference point.
- How far, and how far from — distance and displacement.
- How fast — average speed and average velocity.
- Speeding up — acceleration.
- Steady and changing — uniform and non-uniform motion.
- Reading a graph — what slope tells you.
- Area under the line — displacement, and three equations.
- Round and round — steady speed on a circle.
Need a quick recap?
You met these ideas in earlier classes.
- Speed — distance divided by time.
- Motion in a straight line — a car on a straight road.
- Drawing a line graph — one thing on each axis, with scales.
Begin with the plainest question. Where is the bus?