Question

A circular frame made of 20 cm long thin wire is floating on the surface of water. The surface tension of water
is 70 dyne/cm. Calculate the required excess force to separate this frame from water?​

Answer 1

the answer of the following question is

0.014N

Answer 2

Given:

A circular frame made of 20 cm long thin wire is floating on the surface of water. The surface tension of water is 70 dyne/cm.

To find:

The required excess force to separate this frame from water?

Calculation:

We know the relationship between surface tension and force as follows:

$\boxed{\sf \therefore \: T = \dfrac{F}{L} }$

Now, we need to consider the total length of wire in contact with water , hence L = 20 cm.

$\sf \implies \: 70 = \dfrac{F}{20}$

$\sf \implies \: F = 70 \times 20$

$\sf \implies \: F = 1400 \: dyne$

$\sf \implies \: F = 1400 \times {10}^{ - 5} \: N$

$\sf \implies \: F = 14 \times {10}^{ - 3} \: N$

So, the final answer is :

$\boxed{ \bf{ \red{\: F = 14 \times {10}^{ - 3} \: N}}}$