Question

The density of liquid gallium at ${30}^{o}C$ is $6.95g/mL$. Because of its wide liquid range (${30}^{o}C$ to ${2400}^{o}C$), gallium could be used as a barometer fluid at high temperature. What height (in cm) of gallium will be supported on a day when the mercury barometer reads $740$ torr? (The density of mercury is $13.6g/mL$)

• A. $322$
• B. $285$
• C. $165$
• D. $210$

Answer 1

Answer: (C)

The correct option is C $165$

$P=density\times g\times height$

$740torr\approx 98650Pa$

$98630pa=6095kg/m^3\times 9.8m/s^2\times height\left(m\right)$

$Height=1.65m=165cm$