Prob. $4\mathrm{.}2\mathrm{.}15$ p$.$ IP$-50[$Ans: $-33\mathrm{.}8f\frac{t}{s}$;$1\mathrm{.}05g]$

$4\mathrm{.}2\mathrm{.}15$ WP Video A hydraulic jump is a rather sudden change in depth of a liquid layer as it flows in an open channel as shown in Fig. P$4\mathrm{.}2\mathrm{.}15$ and Video V$10\mathrm{.}12.$ In a relatively short distance $($thickness $=l),$ the liquid depth changes from $z_1$ to $z_2,$ with a corresponding change in velocity from $V_1$ to $V_2.$ If $V_1=1\mathrm{.}20f\frac{t}{s},V_2=0\mathrm{.}30f\frac{t}{s},$ and $l=0\mathrm{.}02ft,$ estimate the average deceleration of the liquid as it flows across the hydraulic jump. How many g$\text{'}$s deceleration does this represent?

FIGURE P$4\mathrm{.}2\mathrm{.}15$