A thin flat circular disc of radius 4.5 cm is placed gently over the surface of water. If surface tension of water is 0.07 Nm$^{-1}$, then the excess force required to take it away from the surface is;

Question

Dr. Abubacker · Accepted Answer

[Solution by Claude - not from source] $F=S\cdot2\pi r=0.07	imes2\pi	imes0.045\approx0.0198$ N $=19.8$ mN. Answer (3).

Q. A thin flat circular disc of radius 4.5 cm is placed gently over the surface of water. If surface tension of water is 0.07 Nm$^{-1}$, then the excess force required to take it away from the surface is;

Explanation

Reviewed by Dr. Abubacker

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