How to Measure the Strength of a Magnet ???

You Will Need :

• Metric ruler
• Graph paper
• Tape
• Small plastic toy car
• Small bar magnets

Process :

First,  get  your  racetrack in order. Take a sheet of graph paper and tape it to your table.

Place your ruler alongside your graph paper and line it up with the lines on the graph paper so you know what distance each line indicates (Depending on what graph paper you’re using, your sheet may be ruled in inches or centimeters. Check the ruling on your graph paper to make sure you’re using the appropriate units!).Take out one of the small magnets. The magnet should be the same size or smaller than the toy car. Tape it to the top of the car. Now, put your car on the track. Set the car at the end of the ruler so that the front-facing end of the magnet is lined up with 0. Check your magnets. What end of the magnet makes the car move forward? Make sure that this end is facing the car, and place your other magnet at the other end of the ruler.

It’s time to create a hypothesis. How close does the magnet need to get to the car before the two magnets start to work together to pull the car along? Start your engines! Slowly start to move the magnet along the track, stopping every centimeter. Is the car moving yet? Note how far you had to move the magnet before the car moves. Do this four times, resetting the position of your car and your magnet each time. Record your results for each trial. Now, stick two of your magnets together. Repeat steps 5-7 with your compound magnet. What happens? Does the car move earlier? Later? Continue to add magnets to your pile, starting a new set of trials each time you add a magnet. Remember to put the car back at the beginning each time! When you’re done, take the average of the four results from each set of trials (take the sum of all 4 numbers and divide by 4). This will give you the usual distance that it took for the car to start moving. In this experiment, the results will depend on the weight of your car and magnet and the strength of the magnet. The more magnets you pile up at the end of the track, the farther away they will be when the car starts to move.