Question

The surface tension of a liquid is being measured with a ring as shown. the ring has an outside diameter of 10 em and an inside diameter of9.5 em. the mass of the ring is 10 g. the force required to pull the rij1g from the liquid is the weight corresponding to a mass of 16 g. what is the surface tension of the liquid (in n/m)?

Answer 1

This experimental method of determining the surface tension of a liquid is called the Du Nüoy Ring method. The equation for this is:

σ = F/4πR
where
σ is the surface tension
F is the net force acting on the ring
R is the radius of the center ring

σ = F/4πR = [(16 g - 10 g)(1 kg/1000 g)(9.81 m/s²)]/{4π[(10 m + 9.5 m)/4]}
σ = 9.608×10⁻⁴ N/m