AP Physics Laboratory #4.1: Projectile Launcher

Transcription

1 AP Physics Labratry #4.1: Prjectile Launcher Name: Date: Lab Partners: EQUIPMENT NEEDED PASCO Prjectile Launcher, Timer, Phtgates, Time f Flight Accessry PURPOSE The purpse f this Labratry is t use the -D prjectile mtin equatins t predict a variety f unknwns fr a cmprehensive set f prjectile mtin scenaris and t subsequently test thse predictins. THEORY As discussed in class, an bject underging prjectile mtin in the absence f significant air resistance will underg cnstant velcity mtin in the hrizntal and free fall acceleratin in the vertical. When written in terms f the launch velcity ( v ) and launch angle ( ), the equatins f mtin becme: x x ( v cs ) t y y v y ( v sin ) t v sin gt These equatins can be cmbined t yield a number f useful results, including the equatin fr the maximum height f the prjectile, the range, and the equatin f the path: v xrange sin( ) g y max height gx y tan( ) x ( v cs ) PROCEDURE Experimental Setup Label the experimental apparatus illustratin belw. ( v sin ) g 1 gt Timer

2 PRE-LAB OBSERVATIONS The prjectile launcher has three settings: shrt range, medium range, and lng range. Cnnect the tw phtgates attached t the frnt f the launcher t the timer and recrd the time required fr the prjectile t cver the 10.0 cm distance between the tw phtgates. Recrd the times belw and determine the launch velcity fr each setting: setting: shrt range time first sht (sec) time secnd sht (sec) average time (sec) launch speed: v (m/sec) medium range lng range Vertical distance between the prjectile launcher and the ceiling = _ m Reprted Accuracy f PASCO Prjectile Launcher = ± % OBSERVATIONAL DATA Experiment 1 Maximum Height: Use the equatins f mtin and data frm the table t predict the maximum height t which the launcher can fire the prjectile n the shrt range setting: Predicted Launch Angle fr Maximum Height: Predicted Maximum Height: Nw use the experimental apparatus t determine the actual height t which the prjectile rises using the launch angle that wuld theretically prvide the maximum height: Actual Maximum Height:

3 Experiment - Maximum range and assciated time f flight: Use the equatins f mtin and data frm the table t predict the maximum range fr the prjectile and the assciated time f flight fr the medium range setting: Predicted Launch Angle fr Maximum Range: Predicted Maximum Range: Predicted Time f Flight: Nw determine the actual range and the assciated time f flight using the launch angle that wuld theretically prvide the maximum range: Actual Maximum Range: Actual Time f Flight:

4 Experiment 3 - Brushing the Ceiling: Use the equatins f mtin and data frm the table t predict what launch angle will result in the prjectile just brushing the ceiling fr the lng range setting. Als predict the straight line distance frm the launch pint t the lcatin at which the prjectile is expected t brush the ceiling (nte: this distance is the magnitude f the displacement vectr between the tw pints): Predicted Launch Angle: Predicted -D distance frm launch pint t the spt where prjectile just brushes the ceiling: Nw fire the prjectile at the predicted launch angle fr the lng range setting. Determine hw clse the prjectile came t the predicted lcatin where it shuld just brush the ceiling. Did the prjectile just brush ceiling?: Apprximate distance between predicted and actual lcatins where prjectile is clsest t ceiling:

5 Experiment 4 - Hitting a Target: Use the equatins f mtin and data frm the table t predict the tw launch angles that will enable yu t hit a target that is lcated a hrizntal distance f.00 meters frm the release pint and at the same height as the release pint fr the shrt range setting. Als predict the times f flight fr the tw settings. Launch#1: Predicted Launch Angle: Predicted Time f Flight: Launch#: Predicted Launch Angle: Predicted Time f Flight: Nw use these launcher angles fr the shrt-range setting, fire the prjectile, and recrd the fllwing data: Launch#1: Actual Range: Actual Time f Flight: Launch#: Actual Range: Actual Time f Flight:

6 ANALYSIS/CONCLUSIONS Cmplete the fllwing Table: PREDICTED OBSERVED ABSOLUTE ERROR Exp#1: Maximum Height Exp#: Maximum Range Exp#: Time f Flight Exp#3: Launch t Ceiling Distance Exp#4, Launch#1: Range Exp#4, Launch#1: Time f Flight Exp#4, Launch#: Range Exp#4, Launch#: Time f Flight Nte: Include at least ne sample calculatin fr abslute and relative errr: RELATIVE ERROR sec sec sec % sec sec sec % sec sec sec % Cmment regarding the mst significant pattern(s) yu ntice in the table abve and speculate as t the cause f at least ne f thse pattern(s):