Hypothesis: If a Nerf Gun’s Spring is Stretched, then it will fire a normal dart farther than an unmodified gun because of the extra energy built up in the spring.

Procedure: 

1. Buy 2 Normal Nerf Maverick Rev-6 Models
2. Place a piece of Tape on the gun you are going to modify
3. Using a small screwdriver, take out all of the screws.
4. Take off the grey mechanism that is used to cock the gun.
5. Take out the small retractable barrel.
6. Take out the Spring.
7. Stretch the Spring until it is twice as long as it was, then let it wind itself back up. It should be about an inch longer than when you started.
8. Put your gun back together. Making sure that you put everything back in the right place.
9. Set up the experimental field.  Stake a tape measurer at the 0 inch mark and at the 30 feet mark in a strait line. Set up a block of wood that is 2 inches tall at the 0 mark.
10. Place 3 normal darts (The Kind shown below) Into the unmodified gun.
    

    Image via Wikipedia

11. Place the front of the gun on the wooden block, so the tip of the gun is directly above the 0 mark
12. Fire all three darts. 
13. Record the distance that the darts traveled in Sub columns 1-3 in row 1 of your data table.
14. Repeat steps 11-13 4 times with the Modified (Spring stretched) Gun, effectively filling up the third column of your data table.

 Data Table:

Data Analysis:

Conclusion:

The Data Shows that: If a Nerf Gun’s Spring is Stretched, then it will fire a normal dart farther than an unmodified gun because in Trials #1-15, The Modified Gun fired on average 5.1 feet farther than the Unmodified gun. The fact that the Modified gun fired farther that the gun 12/13 times it was tested supports the conclusion that a Nerf gun that has had its spring stretched will fire farther than an unmodified gun.

This experiment could be improved by running more Experimental and Control Trials.