Scott,+Heba,+Paul,+Danica+-+Sources+of+Error

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Sources of Error

The rocket did not fly directly perpendicular to the ground, due to it being launched at an angle and due to an active wind. Therefore, the average velocity may be actually higher than the value calculated, due to the horizontal distance the rocket travelled.
 * __ Kinematics __**

In calculations, the value of -9.8m/s 2 was used to represent acceleration due to gravity. However, due to the elevation and the latitude of the launching site, this value is approximate, and therefore calculations relating to the force of gravity on the rocket, acceleration during the thrust face, maximum velocity achieved, and the velocity of the rocket upon impact with the ground may be slightly inaccurate.

The variable of air resistance was disregarded in all calculations. Had this variable been considered, acceleration during the thrust phase would have been calculated to be lower, resulting in a lower value for maximum velocity achieved during the thrust phase. In addition, the velocity of the rocket upon impact with the ground would be a lesser value.

The average mass of the rocket was calculated //assuming// that the propellants burn at a constant rate throughout the thrust phase. The slightly inaccurate value of the average mass of the rocket affects the calculation of the force of gravity on the rocket, the acceleration during the thrust phase, and therefore the maximum velocity achieved during the thrust phase.

Variance in the production of the rocket engines may have resulted in launching an engine that did not produce 6N of thrust for 0.81s, as were the values used in calculations. This imprecise value may affect the calculation of the acceleration during the thrust phase and the maximum velocity achieved during the thrust phase.

__** Rocket Design and Flight **__ The parachute did not open during the first flight because it was folded numerous times and wrapped around the metal snap swivel and elastic. In the second trial the parachute was only loosely folded and the snap swivel and elastic were placed at the side of the parachute making the recovery system easier to deploy. Also the nosecone was not properly attached to the hook for the first trial; it was secured with packing tape in the second trial.

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