-->

Units And Measurement

Question
CBSEENPH11019890

Just as precise measurements are necessary in science, it is equally important to be able to make rough estimates of quantities using rudimentary ideas and common observations. Think of ways by which you can estimate the following (where an estimate is difficult to obtain, try to get an upper bound on the quantity) :

(a) the total mass of rain-bearing clouds over India during the Monsoon.

Solution
straight A space Metrologist space records space about space 215 space cm space of space rainfall space in space India

space straight i. straight e. comma space the space height space of space water space column comma space straight h space equals space 215 space cm space equals space 2.15 space straight m

Ares space of space country comma space straight A space equals space 3.3 space cross times space 10 to the power of 12 space straight m squared

So comma space

Volume space of space rain space water comma space straight V space equals space straight A cross times space straight h space

space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space space equals space 7.09 space cross times space 10 to the power of 12 space end exponent straight m cubed space

Density space of space water comma space straight rho space equals space 1 space cross times space 10 to the power of 3 space end exponent kg space straight m to the power of – 3 end exponent

Therefore comma space

Mass space of space rain space water equals straight rho space cross times space straight V space equals space 7.09 space cross times space 10 to the power of 15 space end exponent kg space

Hence comma space total space mass space of space rain space bearing
space clouds space over space India space equals space space 7.09 space cross times space 10 to the power of 15 space end exponent kg space