# Fast and Easy Science Fair Projects: Down-Range Shooter

Updated on December 30, 2019
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Purpose: The purpose of this experiment is to determine the angle of trajectory that will give the greatest distance.

Overview: When you throw a stone a little upward and away from you, you know that it will not keep going in that direction, but will slowly curve and begin to fall to the ground. The path of an object hurled through the air is called its trajectory. This path is caused by the motions of the stone, moving forward and moving upward at first, then downward. The stone moves upward and forward because the forward because of the force of your throw. but, because the stone force at which it is thrown and its upward angle are both factors.

Hypothesis: Hypothesize that the launch angle of an angle the distance it will travel away from the launching device.

You need:

• wooden ruler
• utility knife
• rubber band
• domino's
• table
• protractor

Procedure: Because of the hazard of using a sharp tool, have an adult cut a small notch at each inch or centimeter mark on a wooden ruler with a utility knife or razor.

Stretch a rubber band from one end of the ruler to one of the notched at a marking, giving it a good stretch, but not to its maximum stretch potential. Hold the ruler lengthwise with one hand neat the edge of a table. With the other hand, push the rubber band out of the notch until it launches. Place a domino on the floor to mark the spot where it landed. Always keep safety in mind; do not launch the rubber band while anyone is standing in front of the ruler.

Then raise the end of the ruler by placing domino's under it. Experiment with different heights (elevation). By launching the rubber band from the same marking, the launch force is kept Constant, and only the angle is Variable.

Set a protractor on the table and measure the angle of the ruler is elevated upward before each launch. What is the angle that shoots the rubber band the farthest distance from the ruler? What is the angle that, if the angle is the farthest increased, the rubber band will not travel any farther (this is the optimum angle for distance)?

Note: If the rubber band gets caught on some of the other notches in the ruler as it launches, you can put tape over them, or make a horizontal cut in a straw and cover the notches.

Results and Conclusion: Write down the results of your experiment. Come to a conclusion as to whether or not your hypothesis was correct.

Something more: 1. The distance the rubber band will travel depends on both the launch angle and the launch force. Try launching the rubber band from different notches, which changes the force. The more the rubber band is stretched, the more force it will have when it is launched. What combination of tilt angle and launch force (marked notch) makes the rubber band travel the farthest? The highest?

2. Make a game by having a friend place a domino on the floor while you tr different combinations of force and tilt to land the rubber band as close as you can to the target. Then reverse places with your friend, and see who can come closest with the least number of tries.

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