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 science fair project idea explores how length affects the weight a bridge can hold.

The objective of this science project is to determine the length of time for different seeds to germinate.

This science fair project idea investigates how the height at which a pendulum is released affects the length of time it continues.

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.

Introduce your fourth grader to the concepts of solstices by observing the length of her shadow on the shortest day of the year, compared to other solstices.

In this classic Ivory soap experiment, kids learn what happens to different types of soap in the microwave, and why!

Learn how starch and carbohydrates interact with different solvents in this fun and easy packing peanut science fair project.

In this experiment you observe and determine how well your cat uses his whiskers to navigate through a maze.

Here's a fun math and science activity: help your child explore four different kinds of measurement, using their hand and a few simple household tools.

Introduce your child to science with something they see everyday--their shadow!

Find out whether soil amendments can improve soil conditions and help you grow a bigger beanstalk in this ecology experiment!

Science fair project that examines the behavior of water and gravel in creek beds and the formation of sedimentary rocks.

This science fair project idea explores whether it is easier to balance on a narrow ledge or on a rope.

Find out whether a longer airplane will fly farther or a wider paper airplane.

In this popcorn experiment, students can explore how two things made out of the same material can have very different appearances and densities.

Take to the air with science by experimenting with helicopter seeds right in your own backyard!

This science fair project idea investigates how color affects temperature.

Did you know your body is full of simple machines? This project looks at one of the third-class levers in the human body: your arm!

Has your kid noticed how much bigger the moon looks when it's low in the sky? Here's an activity you can do to show them that it's just an optical illusion.

This snowman's not abominable, he's adorable! Your child can bring her very own snowman to life while practicing how to create texture.

Want to spark your third grader's interest in gardening? Help him make popsicle stick fairies to decorate an enchanting garden oasis.

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

Bring the fun of gardening indoors! By stuffing a simple pair of pantyhose with a few grass seeds on top, your child can grow her very own plant pet.

This science fair project idea investigates how optical distances change the apparent size of an object as seen through a magnifying lens.

Your second grader will love this simple soda bottle race car activity. Make a ramp and customize your car for an entertaining way to learn scientific concepts.

Using a toy race car kids create a visual model of the Doppler Effect.

We all know that the Moon has different phases, but it can be hard to figure out why. Try this activity to see how the Moon's phases really work.

This science fair project idea investigates the difference in reaction times between boys and girls.

Learn how to make a ping pong ball anemometerâa device used to measure wind speedâin this free science fair project idea.