An inventor has suggested an inexpensive, simple method for determining the speed

at which a small motorboat is travelling. His invention is nothing more than a pipe

with a $90-$degree elbow at the lower end. When placed in the water, as shown in

figure, a fountain of water flows from the upper end of the pipe. To calculate the

boat's speed, the maximum height $L_1$ that the water stream reaches above the end

of the pipe is measured to be $1\mathrm{.}0$ m $.$ In addition, the length of the pipe $L_2=1\mathrm{.}5m$

and the depth of the opening below the surface $L_3=0\mathrm{.}5m$ are known. Considering

the flow with respect to the boat to be steady, calculate the value of the boat speed

$V_b.$