Question

At what speed will be the velocity head of stream of water be 40 cm. g = 980cm/m2​

Answer 1

Given:

The stream of water is 40cm.

g = 980cm/m²

To Find:

At what speed will be the velocity head of the stream of water be equal.

Solution:

Head of mercury (Hg) column, h = 40cm

Changing its unit from cm to m.

40 will be divided by 10 to change into m.

So, h = 0.4m

Head of water = head of mercury × relative density of mercury

⇒ 0.4 × 13.6

⇒ $h_{water}$ = 5.44m

Now, the velocity head using the relation,

Velocity head = 40cm of Hg column hw = h×13.6cm of the water column.

Then, Velocity head of the stream of water is, v = $\sqrt{2 *g *h_{water} }$

                                                                             v = $\sqrt{2 * 9.81 * 5.44}$

                                                                             v = 10.33m/s

Therefore, the speed that will be the velocity head of the stream of water is 10.33m/s.