A U$-$tube open at both ends is partially filled with heavy liquid. Light liquid of density $\backslash (751\backslash$mathrm$\{$~kg$\}/\backslash$mathrm$\{$m$\}^\{3\}\backslash )$ is then poured into the right arm and forms a column $5\mathrm{.}68$ cm in height.

What is the difference in the heights of the two liquid surfaces? The acceleration of gravity is $\backslash (9\mathrm{.}8\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}^\{2\}\backslash ).$

Answer in units of cm $.$

part $2$ of $2$

The right arm is then shielded from any air motion while air is blown across the top of the left arm until the surfaces of the two liquids are at the same height.

Find the speed of the air being blown across the left arm. Assume that the density of air is $\backslash (1\mathrm{.}25\backslash$mathrm$\{$~kg$\}/\backslash$mathrm$\{$m$\}^\{3\}\backslash ).$

Answer in units of $\backslash (\backslash$mathrm$\{$m$\}/\backslash$mathrm$\{$s$\}\backslash ).$