Precise measurements of physical quantities are a need of science. For example to escertain the speed of an aircraft, one must have an accurate methi=od to find its positions at closely separated instants of time. This was the actual motivation behind the discovery of radar in World War II. think of different examples in modern science where precise measurements of length, time, mass etc, arc needed. Also, whereever you can, give a quantitative idea of the precision needed.

Explanation

Extremely precise measurements are needed in modem science. As an example, while launching a satellite using a space launch rocket system we must measure time to a precision of 1 micro second. Again working with lasers we require length measurements to an angstrom unit `(1 A^(@)=10^(-10) m)` or even a fraction of it. for estimating nuclear sizes we require a precision of `10^(-15)m`. To measure atomic masses using mass spectrograph we require a precision of `10^(-30)`kg and so on.