Grayed Demos are either not available, haven't been built yet, and or new ideas

PIRA #

Demonstration Name

Abstract

2A10.10

soap film pullup

A soap film pulls a sliding wire up a "U" shaped frame.

2A10.11

sliding wire

A sliding wire frame film with a spring on one end and a string pull on the other shows that tension does not increase with length.

2A10.15

submerged float

A cork and lead device floats with a wire ring above the surface. Push the ring below the surface and it remains until soap is added to reduce the surface tension.

2A10.20

floating metals

Float needles, paperclips, rings of wire, etc. on water.

2A10.21

floating metal sheet

Float a sheet of metal on the surface of distilled water and add weights until the metal sinks.

2A10.25

leaky boats

Try to float several large (one foot long) flat bottomed boats made of different screen material or aluminum with different size holes. A screen boat, razor blade, or small metal boat with a large hole all float on water.

2A10.30

surface tension/Adhesion balance

An improved method for measuring surface tension by the direct pull method. A glass plate on one end of a balance beam is in contact with a water surface.

2A10.32

pull on the ring

Pull a large ring away from the surface of a liquid with a spring sale.

2A10.33

surface tension disc

A flat glass disc on a soft spring is lowered onto the surface of distilled water and the extension upon pulling the disc off the water is noted.

2A10.35

cohesion plates

There is a difference in cohesion of dry and wet plate glass. Glass plates stick together when a film of water is between them.

2A10.37

cohesion plates fallacy

If they demonstrate cohesion, why do they fall apart when placed in a bell jar that is evacuated? Atmospheric pressure holds two plate glass panes together.

2A10.38

cohesion tube

A long (2-4 m) tube full of water and sealed at the top will support the water column against gravity.

2A10.40

drop soap on lycopodium powder

Sprinkle lycopodium powder on the surface of water, then place a drop of liquid soap on the surface.

2A10.50

bubbles blowing bubbles

Blow bubbles of different size on a "T" tube. The smaller soap film bubble blows up the larger one.

2A10.52

rubber balloons

The equation relating the internal pressure to the radius is derived and applied to the problem of the two interconnected unequal balloons.

2A10.55

pressure in a bubble

Connect a slant water manometer to a tube supporting a bubble. Vary the size of the bubble and note the change of pressure.

2A10.68

sponge action

Water picked up by a wet sponge is greater than that picked up by a dry one.

2A10.71

rolling drops

A drop of alcohol can roll on the surface of an alcohol dish.

2A10.73

Plateau's spherule

A method of projecting and strobing drops forming down from a vertical orifice.

2A10.74

bursting water bubble

A jet of water directed upward against the apex of a cone will cause the water to flow around and form a bubble. A drop of ether will decrease the surface tension and the bubble will collapse.

2A10.80

effect of charge on surface tension

Dripping rate is much greater from an electrically charged buret.

2A10.81

surface tension with electric field

Droplets from a orifice become a steady stream when connected to a Wimshurst generator.

2A10.83

electrostatic breakdown of surface t

Droplets shoot out of a pond of carbon tetrachloride on a Van de Graaff generator as electrostatic breakdown of surface tension takes place.

2A10.84

elecrostatic dispersion of water drop

Water drops from a pipette at high potential are dispersed into droplets.

2A10.85

changing drop size

As the amount of sodium hydroxide is varied in a dilute solution, the size of drops formed by a olive oil jet changes with the variation of surface tension.

2A10.95

temperature effects

Olive oil sprayed on hot water forms droplets but on cold water forms a slick.

PIRA #

Demonstration Name

Abstract

PIRA #

Demonstration Name

Abstract