This science fair project creates a visual model of whatâs happening to sound waves as a car approaches and then leaves.

Learn about magnifying glasses, concave lenses and inverted images by sending rays of light through a magnifying glass in this cool science fair project!

Learn how to tell time by the sun with this cool science fair project idea that tracks how the accuracy of a sundial changes over time.

Magnets vary in strength. Have your young scientist figure out which kind of magnet is the strongest when you have him conduct this attractive experiment.

Create a DIY Electromagnet! Using a 9v battery to create an electrical field around a nail, students explore electromagnetism in this cool science project idea.

In this project, all you need is a protractor to learn how to use the altitude of Polaris to find latitude on Earth. Polaris is also known as the North Star.

In this free science fair project, build a star clock and learn how to tell time on a clear night by observing the big dipper!

This science fair project idea investigates how color affects temperature.

This science fair project idea explores if the length of the string that an object is suspended on has an effect on how fast or slow it swings.

This project compares the strength of one, two, and three-ply toilet paper.

What causes the seasons to change? Kids find out by modeling the earth's tilt using a globe, flashlight and graph paper in this cool science fair project idea.

This science fair project idea investigates if heat from direct sunlight is hotter than heat from reflected sunlight.

Is it amplitude? Weight? Length of string? Kids will discover what factors changing the period of a pendulum depends on in this fun and easy physics experiment.

Handedness and footedness refer to whether people prefer to use their left or right hand and foot. In this experiment, test hand and foot dominance.

In this science fair project, we'll use a liquid crystal thermometer to find out whether exercising makes a difference in people's temperature.

This science fair project examines how seeds hitchhike on animals and clothing.

This science fair project teaches kids experimental design and how to test if subjects can really sense if they are being watched.

Kids learn how to prevent erosion by growing grass. They'll test soil with grass against raw soil in this revealing science fair project idea for 4th grade.

In this science fair project, students create their own miniature salt flats at home.

This science fair project idea examines whether boys and girls differ in reflexes.

Construct and experiment with a periscope using reflected light rays to gather an image.

This science fair project idea examines whether the colors of the spectrum respond differently in the thermal aspect when radiated by the sun.

In this fun science fair project, make two different scale models of our solar system using Astronomical Units and planets' relative size!

Saturn is the ringed planet in our solar system, a gas giant with rings made of ice and dust. Let's make a cool scale model with an old CD and some glitter!

In this science fair project, you'll make a "ghost" appear in a test tube, and learn about what happens when hot water and cold water interact.

Science fair project examining barometric pressure, and how it can be used to predict the weather. How does atmospheric pressures relate to weather conditions?

In this science fair project, students make their own rain gauge to measure rainfall.

Can a toy car determine the strength of a magnet? In this cool magnet science fair project, young scientists will learn how to measure the strength of a magnet.

Want to see a great example of Newton's first law? Kids will learn about basic physics with this fun, ballistic experiment.

Check out this fun and easy 4th grade science fair project idea that tests how gravity induces positive and negative geotropism (gravitropism) in bean plants.