Name the S.I. unit of time and define it.
Name the S.I. Unit of mass and define it.
(a) What is meant by the 'time-period' of a vibrating object? State its unit.
(b) Define 'frequency' of a vibrating object. Name the unit in which frequency is measured.
(c) A pendulum oscillates 40 times in 4 seconds. Calculate its (i) time-period. and (ii) frequency. Can we hear the sound produced by the oscillations of this pendulum? Give reason for your answer.
Define time. What is the most ancient unit of time?Define it.