Both limbs of a U-tube are 40 cm long. The sealed limb holds a 40 cm column of air at 76 cm Hg, closed off by mercury. The other limb is then filled to the top with mercury. Find the new height of the

Question

Both limbs of a U-tube are 40 cm long. The sealed limb holds a 40 cm column of air at 76 cm Hg, closed off by mercury. The other limb is then filled to the top with mercury. Find the new height of the air column in cm (two decimals). Atmospheric pressure is 76 cm Hg.

TestHub · Accepted Answer

With air length x , the mercury in the sealed limb rises 40 − x , so P = 76 + 40 − ( 40 − x ) = 76 + x . Isothermal: 76 × 40 = ( 76 + x ) x , so x 2 + 76 x − 3040 = 0 and x = 28.96 cm.

Physics - Heat & Thermo Question with Solution | TestHub

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