Answer :
Final answer:
Water rises in a capillary tube due to surface tension, calculated using specific formula with key variables.we calculate the surface tension of water by using the ratio of the heights adjusted for the fact that water rises and mercury falls.
Explanation:
Water rises in a capillary tube due to the cohesive and adhesive forces acting on it. In this case, the surface tension of water can be calculated using the formula h = (2T cosθ)/( ρgr), where h is the height, T is the surface tension, θ is the contact angle, ρ is the density, g is acceleration due to gravity, and r is the radius of the tube.
To find the surface tension of water, we can use the ratio of the heights and the known surface tension of mercury because the density, gravity, and capillary radius are consistent for both liquids in the same tube. Since water rises to 9 cm and mercury falls by 3.4 cm, and given the surface tension of mercury is 0.5 N/m, we calculate the surface tension of water by using the ratio of the heights adjusted for the fact that water rises and mercury falls.
