Question

The normal duration of Physics practical period in indian college is 100 minutes. Express this period in microcentury. 1 microcentury = ${10}^{-}6\times 100$ years. How many microcenturies did you sleep yesterday?
The surface tension of water is 72 dyne/cm. Convert it in SI unit.

Answer 1

(1) Given that,

$1microcentury={10}^{-6}\times 100years$

$={10}^{-4}\times 365\times 24\times 60min$

$so,$

$100min=\frac{100}{525600\times {10}^{-4}}$

$=1.9microcentury$

Consider that the person sleeps for 6 hors in a day i.e. almost 360 min.

So, $360min=\frac{360}{525600\times {10}^{-4}}$

$=6.84microcentury$

(2) surface tension of water is $=72dyne/cm$

In SI unit, $72dyne/cm=0.072N/m$