The unit for surface tension is one newton per meter (N/m).

If the density of the liquid is not given, you can look it up in a reference book or calculate it using the equation density = mass/volume.

When working through this equation, make sure all of your units are in the proper metric form: density in kg/m 3, height and radius in meters, and gravity in m/s 2.

Surface tension is given by the equation S = (ρhga/2) where S is the surface tension, ρ (or rho) is the density of the liquid you are measuring, h is the height the liquid rises in the tube, g is the acceleration due to gravity acting on the liquid (9.8 m/s 2) and a is the radius of the capillary tube.

Rest the nail horizontally between two stacks of books so that the center beam can rotate freely.ĭefine the equation to solve for surface tension.

Make sure that there is 1 string for each hole at either end. Thread a string through each hole to serve as holders for the balance dishes.

Drill or poke a hole at each end of the beam ensuring that they are the same distance from the middle.

If you are using a plastic straw you can just poke a pin or nail right through it.

Mark the center of the material to be used for your beam (straw, plastic ruler) and drill or poke a hole through it this will be the fulcrum point (the point that allows the beam to rotate freely).

You can use many different types of materials for this, just make sure the center beam is something sturdy like wood, plastic, or dense cardboard. The balance beam needs to be well constructed so that you can get an accurate result. X Trustworthy Source Science Buddies Expert-sourced database of science projects, explanations, and educational material Go to source In this experiment, you will use a balance beam and a small needle floating on the surface of water to measure surface tension. You can measure surface tension with a few household items and a calculator.Ĭonstruct a small balance beam. X Trustworthy Source Science Buddies Expert-sourced database of science projects, explanations, and educational material Go to source The forces that water molecules exert on each other, or cohesive forces, cause the tension and are responsible for the shape of water (or other liquid) drops. These are measured as Newton per meter (or N/meter).

Surface tension is measured by the amount of force (N) exerted on a unit such as length (m) or the amount of energy of a measured area. X Trustworthy Source Science Buddies Expert-sourced database of science projects, explanations, and educational material Go to source Surface tension is what allows a denser object, such as an insect, to be able to float on the water's surface. For example, water forms droplets on a table because the water molecules at the surface group together against the force of gravity.

Surface tension refers to the ability of a liquid to resist the force of gravity.

Surface tension half life