Chapter 5 — Measurement of Length and Motion
Curiosity: Textbook of Science, Grade 6 · pages 79–100
Lesson
The full chapter: 18 key terms, 9 concepts, 13 figures described, and every end-of-chapter question.
Revision Sheet
Unit conversions, the four rules of measuring correctly, how to write units, and the three types of motion with examples.
Flashcards
33 click-to-flip cards in 5 decks, plus a rapid-fire drill. Shuffle them for a harder run.
Mind Map
Measuring → standard units → measuring correctly → reference point → motion and its types.
Question Bank
35 written questions, 52 marks — fill in the blanks, true/false, match, short and long answers, and HOTS.
MCQ Quest — 50 questions
5 levels. No answers revealed until you finish, then a full review — plus a rank badge and XP bar at the end.
What this chapter is about
Deepa, an eleven-year-old from Haryana, needs a new uniform — and wonders why the tailor uses a tape, the shopkeeper a rod, and her mother says char angula. With her friends Anish, Hardeep, Padma and Tasneem, she discovers that body-part units (handspan, arm, stride) give different answers for different people, which is why the world adopted standard SI units — the metre. The chapter teaches the correct way to measure (placing the scale, eye position, broken scales, curved lines), how to write units, and then moves to position: the reference point, what motion and rest really mean, and the types of motion — linear, circular, oscillatory and periodic.
The six things most worth remembering
1 · Body parts don't agree
Five friends measured the same table as 13, 14, "slightly more than 13"… because handspans differ. A length = number + unit.
2 · SI unit of length = metre (m)
1 km = 1000 m · 1 m = 100 cm · 1 cm = 10 mm. A 15-cm scale can measure down to 1 mm.
3 · Measure correctly
Scale in contact along the length; eye directly above the point; broken scale → start at a full mark and subtract; curved line → thread or flexible tape.
4 · Reference point
A fixed object or point from which distance is stated — the bus stand, Delhi on a kilometre stone.
5 · Motion vs rest
An object is in motion if its position changes with respect to a reference point with time; otherwise it is at rest. It depends on the reference point you choose.
6 · Three types of motion
Linear (straight line), circular (circular path), oscillatory (to and fro). Circular and oscillatory are periodic.