Question #57bf5

1 Answer
Jan 17, 2018

Let the cross section of the barometric tube be acm^2 and atmospheric pressure is p cm of Hg.

So initial volume of air column V_1=10acm^3

And initial pressure of the air column P_1=(p-72) cm of Hg.

Again final volume of air column V_2=8acm^3

And initial pressure of the air column P_2=(p-71) cm of Hg.

By Boyle's law we can write.

(p-72)*10a=(p-71)*8a

=>10p-720=8p-568

=>10p-8p=720-568

=>2p=152

=>p=152/2=76 cm of Hg.