A U$-$tube open at both ends is partially filled with water. Oil having

a density $750$ kg$/$m$3$ is then poured into the right arm and forms a

column L $=5\mathrm{.}00$ cm high. $($a$)$ Determine the difference h in the

heights of the two liquid surfaces.

$($b$)$ 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 $($c$).$

Determine the speed of the air

being blown across the left arm.

Take the density of air as $1\mathrm{.}29$

kg$/$m$3$