Possible open ended experimental investigations

Energy in a balloon
Drag on small boats – use a piece of guttering
Energy in a light bulb – LDR etc. – colour effects
Extension of the wire experiment – surface area/bolometer
Cars and carpet – braking experiments
Defects of a lens - astigmatism
Mixing water and methanol
Stretching a rubber band – heat effects
Expansion of a loaded rubber band when it is heated
The propeller and drag
Strength of plants – bending in the wind
Resonance in buildings – earthquake simulations
Mechanical resonance
The bifilar suspension
Growth of current in a light bulb
Absorption of light by glass
Waves on a stretched spring
Potential on a van der Graaff – paper levitation
Diffraction and resolution
Oscillation of tapes in an airflow
Falling magnet
Singing tube
Attractive forces in electromagnets
Fatigue in aluminium strips
Craters
Bouncing balls
Friction in curtain rails
How bubbles arise in liquids
Effect of polish on friction
The strength of adhesives
Vibrations in a soap film
Viscosity of liquids
Optical properties of treacle
Objects in an air stream
Standing waves on a vibrating wire hoop
The jumping ring
Penetration of nails into wood
Photochromic sunglasses
Bending of a beam
Electromagnetic clutch
Strengths of wet and dry tissues
Capillarity in sugar cubes
Thrust of model aircraft propellers
Transformer efficiency
Transmission of light through glass and water
Conductivity of salt solution
The silt meter
The properties of a small water pump
Strength of a polythene bag
Forces in athletics
Damping and resonance
Reflection of microwaves from mesh of different sizes
The efficiency of a small solar cell
Electromagnetic induction – separated coils – thickness measurement
Air damping with a propellor

Some further comments on "open ended" experiments

In these experiments you cannot be sure what you will find - you won't find them written up in any book so it is especially necessary that you plan them carefully.
Before starting ask yourself these questions and be able to answer them!