Question

Fluids have a surface tension, which means that requires that creating more surface requires energy. In order to create more water surface (for example, water spreading over a table top), an energy cost must be paid of about 73 mJ/m2. Lets say you have water in a rectangular container that is 26 cm by 16 cm. Now you want to stretch the longer side by 7 cm. With what force does the surface tension of the water resist that change

Answer 1

To calculate the force required to stretch the longer side of the rectangular container by 7 cm, we can use the formula: Force = Surface Tension x Change in Surface Area. The surface tension of the water resists the change with a force of approximately 0.08176 N.

Step-by-step explanation:

Surface tension is the energy required to increase the surface area of a liquid. It is measured in units such as joules per square meter (J/m²). In this case, the surface tension of water is approximately 73 mJ/m².

To calculate the force required to stretch the longer side of the rectangular container by 7 cm, we need to determine the change in surface area. The original surface area of the longer side is 26 cm by 16 cm, which is 416 cm². After stretching, the surface area will be 33 cm by 16 cm, which is 528 cm². The change in surface area is

528 cm² - 416 cm² = 112 cm².

To calculate the force, we can use the formula:

Force = Surface Tension x Change in Surface Area

Force = (73 mJ/m²) x (112 cm²)

Force = 8,176 mJ = 0.08176 N

Therefore, the surface tension of the water resists the change with a force of approximately 0.08176 N.