Question

Oil stored in a large open tank flows through a narrow opening in it towards its bottom

with a speed of 20 m/s. Find the depth of the narrow opening in that tank?​

Answer 1

Given:

Oil stored in a large open tank flows through a narrow opening in it towards its bottom with a speed of 20 m/s.

To find:

Depth of narrow opening ?

Calculation:

Since the question clearly mentions that the lower opening of the tank is narrow (i.e. insignificant) as compared to the large cross-section of the tank, we can easily use TORICELLI'S LAW:

Let the depth be "h":

As per TORICELLI'S LAW:

$\sf \therefore \: v = \sqrt{2gh}$

$\sf \implies \: {v}^{2} = 2gh$

$\sf \implies \: h = \dfrac{ {v}^{2} }{2g}$

$\sf \implies \: h = \dfrac{ {(20)}^{2} }{2 \times 10}$

$\sf \implies \: h = 20 \: m$

So depth of opening is 20 metres.