Question

Determine the height above the dashed line XX' attained by the water stream coming out through the hole is situated at point B in the diagram given. Given that $h=10$m, $L=2$m and $d={30}^o$.

• A. $10$m
• B. $7.1$m
• C. $5$m
• D. $3.2$m

Answer 1

The correct option is D $3.2$m

Given that,

Height $H=10m$

Length $L=2m$

Angle $\theta ={30}^{\circ }$

According to the figure,

From the figure h is

$h=2\times \sin \theta$

$h=2\times \sin {30}^{\circ }$

$h^{\prime }=1m$

Now, apply Torricelli's law, velocity of jet will be

$v=\sqrt{2g(H-h)}$

$v=\sqrt{2\times 9.8(10-1)}$

$v=13.3m/s$

Now,Height of the jet from the opening of orifice at lower end

$H^{\prime }=\frac{v^2{\sin }^2{30}^{\circ }}{2g}$

$H^{\prime }=\frac{13.3\times \left(\frac{1}{2}\right)}{2\times 9.8}$

$H^{\prime }=2.2m$

Height from the line XX' will be,

$H=H^{\prime }+h$

$H=2.2+1=3.2$

So, the maximum height of the jet is $3.2m$

Hence, D is correct option.