Important Questions on Time and Motion
What is the most ancient unit of time? Define it. 
What is a pendulum? What for a pendulum is used? What kind of measuring device you will use, (i) to tell time at any place (ii) to tell time for -meter race? What is the SI unit of time? Name its four multiples. Starting from solar day, write all the sub-multiples of time and state their magnitudes. Who invented sundials in India? Name the places where these sundials are located. Why do we say that rest and motion are relative terms? Define variable speed. Support your answer by two examples. 
