# Magnet Science Fair Project: Measure the strength of a magnet?

We’re going to the magnetic racetrack! Get your motors ready. This cool magnet science fair project will teach you how to measure magnet strength using a ruler, graph paper and a toy car.

### Problem:

Is it possible to measure the magnet strength of a magnetic toy?

### Materials

• Metric ruler
• Ideal for graph paper (4×4 inches)
• Tape
• A small, plastic toy car that can move freely. This is why you should avoid using a windup vehicle.
• Bar magnets for small bars (minimum 4).

Procedure

1. Get your racetrack organized. Tape a piece of graph paper to your table.
2. Line up your ruler with your graph paper. Make sure to check the ruler on your graph paper for the correct units!
3. Grab one of the small magnets. The magnet should be approximately the same size as the toy car. Attach it to the car’s top.
4. Place your car on the track. Place the car on the track so that the front-facing magnet end is parallel to the ruler.
5. Make sure you check your magnets. Which end of the magnet causes the car to move forward? Place your magnet on the opposite end of the ruler so that the car faces this end.
1. Now it’s time for a hypothesis. How close should the magnet get to the car in order for the two magnets to pull it along?
2. Start your engines! Slowly move the magnet along the track. Stop every centimeter. Does the car move yet? Take note of how far the magnet had to be moved before it moved. Repeat this four times, setting the magnet and car’s position each time. Keep track of your results each time.
3. Now stick two magnets together.
4. With your compound magnet, repeat steps 5-7. What happens? Is the car moving earlier? Later?
5. Continue adding magnets to your pile. Each time you add a magnet, a new set is created. Always put the car back where it was at the beginning!
6. Once you are done, add the four trials results together. Divide the total by 4. This will give you an estimate of the distance it took for the car’s to move.

The bar magnet moves in your pocket, purse or tote to bring you the little things that you need if you want them. Whether you need a phoneestone for your auto or a business card case for the notebook the magnet maybe handy tool. The creation of the bar magnet was created by an American Silversmiths and it took many years to perfect the design. The first designs were quite crude and unappealing but today they have a wonderful slick look in them that makes them the perfect companion for your home, office or travel bags. When you want something useful and you’ve got somewhere to put it afterward the Bar magnets can give you a hand.

### Results

The results of this experiment will depend on your car’s weight and the strength of the magnetic field. The closer you are to the car’s start of moving, the more magnets will be at its end.

### Why?

Amazing magnets! A magnet can move objects even though you cannot see any pulling or pushing. The magnets will work together if one magnet’s pole (or north end) faces another magnet’s pole (or south). The magnets will move away if the poles are facing each other. Magnetic fields are invisible and are created by the movement electrical charges. Although you cannot see the magnetic field, you can see its results. Your toy car moves because of the magnet’s pull between its north and south poles. The pull is stronger if there are more magnets.

What could possibly change the outcome of this experiment?

Different toys cars weigh different amounts. Different magnets can also be different in weight. Attaching the magnet to a car makes it heavier. A heavier car requires more magnetic force.

Some cars also have wheels that are more agile than others. They are less likely to cause friction with the rest of your car. Friction is when an object rubs against another. This slows down the car.

Your experiment will be affected by the magnet’s power. You will find that magnets with different strengths can be placed on top of one another. Some magnets can be very small, but they are extremely powerful. Rare earth magnets can move your car even if they are far from it. Toy magnets have a lower power.

What other factors could affect the results of your experiment’s success? You can try this experiment with different magnets and cars. Which combination is the easiest to move? Which combination is the most difficult?