NCERT Solutions for Curiosity Chapter 8 Measurement of Time and Motion

About this chapter

People first kept time by watching events in nature that repeat after definite intervals — the rising and setting of the Sun, the phases of the Moon, the changing seasons. From these they made calendars, and then devices for smaller intervals within a day: sundials , water clocks , hourglasses and candle clocks . India has a rich record of timekeeping. Shadow-based measurement appears in Kautilya's Arthasastra , and Varahamihira gave an accurate expression around 530 CE. The sinking-bowl water clock or Ghatika-yantra , first mentioned by Aryabhata, took 24 minutes to fill and sink — so a day was divided into 60 ghatis . The Samrat Yantra at Jantar Mantar, Jaipur, is 27 m tall and can measure intervals as short as 2 seconds . A simple pendulum is a small metallic ball (the bob ) hung from a

• .1 Measurement of Time
• .1.1 A simple pendulum
• .1.2 SI unit of time
• .2 Slow or Fast · 8.3 Speed
• .3 Speed
• .4 Uniform and Non-uniform Linear Motion
• Chapter exercises
• Interdisciplinary projects
• Interdisciplinary task