One angular metal ring of inner radius 7 cm and outer radius 14 cm and of negligible weight is floating on the surface of a liquid. If surface tension of liquid is `0.08Nm^(-1)`, calculate the force required to detach it from liquid surface.

Explanation

To solve the problem of calculating the force required to detach the angular metal ring from the liquid surface, we can follow these steps:

### Step 1: Understand the Geometry of the Ring
The ring has an inner radius \( r_1 = 7 \, \text{cm} \) and an outer radius \( r_2 = 14 \, \text{cm} \). We need to calculate the total contact length of the ring with the liquid surface.

### Step 2: Calculate the Contact Length
The contact length \( L \) of the ring with the liquid surface can be calculated using the formula for the circumference of a circle. Since the ring has both an inner and an outer circumference, we can express \( L \) as:
\[
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