Measurement of Time and Motion

This topic explores how humans have measured time through history—from sundials and water clocks to pendulums and atomic clocks—and introduces the concept of speed as the distance covered per unit time. It also distingui…

• Early humans used repeating natural events — sunrise, Moon phases, seasons — to define day, month and year.
• A sundial measures time by the changing position of a shadow cast by sunlight.
• Water clocks measure time by the flow of water into or out of a vessel; the outflow type slows as water level drops.

Full explanation, worked examples & memory tricks in the app