IYPT 2005 – Winterthur, Switzerland
Propose a model of how a dragonfly flies. Investigate the major parameters and validate your model.
The two ball problem
Two balls placed in contact on a tilted groove
sometimes do not roll down. Explain the phenomenon and find the conditions,
under which it occurs.
Under what conditions may an avalanche occur?
Investigate the phenomenon experimentally.
When a smooth column of water hits a horizontal
plane, it flows out radially. At some radius, its height suddenly rises.
Investigate the nature of the phenomenon. What happens if a liquid more viscous
than water is used?
Create a mirage like a road or desert mirage in
a laboratory and study its parameters.
When a droplet of water or other liquid falls on
a hot surface, it produces a sound. On what parameters does the sound depend?
The bouncing plug
A bathtub or sink is filled with water. Remove
the plug and place a plastic ball over the plughole. As the water drains the
ball starts to oscillate. Investigate the phenomenon.
Construct a car which is propelled solely by
wind energy. The car should be able to drive straight into the wind. Determine
the efficiency of your car.
Sound in the glass
Fill a glass with water. Put a tea-spoon of salt
into the water and stir it. Explain the change of the sound produced by the
clicking of the glass with the tea-spoon during the dissolving process.
Combine powdered iron (iron filings) with a
vegetable oil. Connect two containers with plastic tubing and allow the mixture
to drain through the tube. Develop an external mechanism to control the flow
rate of the mixture.
If a stream of water droplets is directed at a
small angle to the surface of water in a container, droplets may bounce off the
surface and roll across it before merging with the body of water. In some cases
the droplets rest on the surface for a significant length of time. They can even
sink before merging. Investigate these phenomena.
Spin can be used to alter the flight path of
balls in sport. Investigate the motion of a spinning ball, for example a
table-tennis or tennis ball, in order to determine the effect of the relevant
A mixture of starch (e.g. cornflour or
cornstarch) and a little water has some interesting properties. Investigate how
its “viscosity” changes when stirred and account for this effect. Do any
other common substances demonstrate this effect?
Einstein – de Haas Experiment
When you apply a vertical magnetic field to a
metallic cylinder suspended by a string it begins to rotate. Study this
Take two glass prisms separated by a small gap. Investigate under what conditions light incident at angles greater than the critical angle is not totally internally reflected.
Obstacle in a funnel
Granular material is flowing out of a vessel
through a funnel. Investigate if it is possible to increase the outflow by
putting an “obstacle” above the outlet pipe?
A transparent vessel is half-filled with
saturated salt water solution and then fresh water is added with caution. A
distinct boundary between these liquids is formed. Investigate its behaviour if
the lower liquid is heated.