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Physics experiments and science fair projects

Hands-on physics projects covering motion, forces, light, sound, magnets and energy. Each one lists the exact materials, the time and cost involved, the variables to control and a data table you can fill in — so it works as a class activity or as a full science fair entry.

38 published projects in this collection

Choosing a physics project

Physics projects are the easiest place to get clean, repeatable numbers: distance, time, temperature and mass are all simple to measure at home with a ruler, a stopwatch and a kitchen scale.

What every project includes

A research question and hypothesis, an independent and dependent variable, the variables you hold constant, a materials list with costs, numbered steps, safety guidance and a reproducibility score based on how completely the method is documented.

Projects to try

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Super Easy Bottle Rocket

Build a simple bottle rocket using a vinegar and baking soda reaction in a sealed plastic bottle to produce carbon dioxide, increase pressure, and launch the bottle. Demonstrates gas production, pressure, and Newton's third law.

Beginner
Elementary
Under 30 minutes
$3 materials

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Does nozzle size change how far a water rocket flies?

Launch a bottle rocket with different nozzle openings and compare distances.

Challenging
Middle School +2
Several days
$25 materials

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Does a thicker wire carry current with less loss?

Measure voltage drop across wires of different thicknesses carrying the same current.

Challenging
High School +1
1 day
$20 materials

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Does the shape of a paper cup affect how loud a string telephone sounds?

Build string telephones with different cups and rate how clearly words come through.

Beginner
Elementary +2
30–60 minutes
$5 materials

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Does the length of a marble run change how fast the marble finishes?

Build marble runs of different lengths from the same starting height and time each run.

Beginner
Elementary +3
1–2 hours
$10 materials

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Does the thickness of a homemade speaker coil change the volume?

Build a coil-and-magnet speaker and compare loudness with different coil turn counts.

Challenging
Middle School +2
Several days
$20 materials

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Does the number of pulleys reduce the force needed to lift a load?

Build pulley systems with one, two and three pulleys and measure the force needed to raise the same load.

Intermediate
Elementary +3
1 day
$18 materials

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Engineering · Physics

A Better Hot Tub Cover

This project demonstrates how to build a rigid, insulated hot tub cover designed to reduce heat loss, protect the hot tub from rain and debris, and provide a lightweight but durable covering. The design uses two insulated halves joined with a continuous hinge. The cover combines rigid plastic or wood-like structural material with insulating foam, a moisture barrier, reinforcement, and a flexible perimeter seal.

Challenging
high school +2
1–2 hours
$296 materials

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Does a series or parallel circuit make bulbs brighter?

Wire identical low-voltage bulbs in series and parallel and measure current and brightness.

Intermediate
Middle School +2
1 day
$20 materials

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Does the shape of an object affect whether it floats or sinks in water?

Mould equal amounts of clay into different shapes and test how much weight each shape can float.

Beginner
Elementary +2
1 day
$5 materials

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Does the number of batteries change the brightness of an LED?

Build a simple low-voltage circuit and observe LED brightness as battery cells are added.

Intermediate
Middle School +2
1 day
$12 materials

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Does the thickness of a rubber band affect how far it stretches under the same weight?

Hang identical weights from rubber bands of different thicknesses and measure how much each one stretches.

Intermediate
Middle School +2
1 day
$5 materials

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Does rubbing time affect the strength of a static electric charge?

Rub a balloon against hair for different durations and count how many small paper bits it attracts.

Beginner
Elementary +2
1 day
$3 materials

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Does the thickness of a lens affect how much it magnifies an image?

Compare several magnifying lenses to see whether thicker, more curved lenses magnify text more strongly.

Intermediate
Middle School +2
1 day
$15 materials

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Does altitude change the sound of air escaping a straw?

Use squeezed air from a bottle to push a ping pong ball across a table and measure how squeeze force changes distance.

Beginner
Elementary +3
1 day
$4 materials

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Does the mass of a cart change how fast it accelerates down a ramp?

Roll a cart with different added masses down the same ramp and measure how quickly it speeds up.

Intermediate
Middle School +2
Several days
$15 materials

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Does the temperature of air affect how high a balloon-powered car travels?

Inflate a balloon with air of different temperatures and measure how far a balloon car travels on release.

Intermediate
Middle School +2
Several days
$10 materials

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Does the height of a bounce depend on the surface a ball drops onto?

Drop a ball from a fixed height onto different flooring materials and measure the rebound height as a measure of energy loss.

Beginner
Elementary +3
1 day
$5 materials

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Does the length of a rubber band affect the pitch it makes when plucked?

Stretch a rubber band over a box to different lengths and record the pitch produced when plucked.

Beginner
Elementary +2
1 day
$3 materials

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Does the position of weight on a ruler affect how easily it balances?

Attach a fixed weight at different points along a ruler and find the balance point on a fulcrum each time.

Beginner
Elementary +2
1 day
$3 materials

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Does a magnet work through different materials?

Test how many sheets of different materials a magnet can pull a paperclip through.

Beginner
Elementary +2
30–60 minutes
$5 materials

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Does the colour of a container change how quickly water cools?

Fill identical cups wrapped in different colours with hot water and track temperature over time.

Beginner
Elementary +3
30–60 minutes
$6 materials

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Does stirring speed change how fast food colouring spreads?

Drop dye into still and stirred water and time how long it takes to mix.

Beginner
Elementary +2
30–60 minutes
$3 materials

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Does water depth affect how quickly it heats up in sunlight?

Fill identical containers with different depths of water and track temperature change in sunlight over time.

Beginner
Elementary +3
Several days
$5 materials

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Preparing for a fair? Read the science fair guide or record your data in the lab.