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A race ends in a photo finish. The runners finish almost together. What tells the winner?

Read Chapter 8, Measurement of Time and Motion, in your NCERT book.

What you will do

• Tell which repeats can keep time.
• Change time between hours, minutes and seconds.
• Time a pendulum.
• Calculate speed, and compare two speeds.
• Tell uniform motion from non-uniform motion.
• Find the average speed of a trip.
• Name the old clocks and what each counts. Read the time from a sundial.
• Mark a water clock, and see why the marks come close together.
• Compare how exact clocks are.
• See what the smallest tick of a clock decides.
• Find speed from a railway timetable.

Each lesson starts with a small lab. Read the words after it.

Need a quick recap?

• Standard units (Class 6) — a metre means the same length everywhere.
• Motion along a straight line (Class 6) — called linear motion.