ThunderandLighting

=__**Preparing to Paraschute**__= __Lab Goal:__ How does the weight of an army man affect the time of air resistance?
 * By Meghan F. and Maura S.**

__Supplies:__ •Parachute army man •Paper clips •Timer •Scale •Meter Sticks •Video Camera- for visual representation

__Procedure:__ 1. Unwrap army man, then weigh it

2. Using the formula's df=di+vit+1/2at^2, find the "ideal time", or the time without air resistence

3. Measure the distance at which you are dropping the army man by dropping a sting then measuring it.



4. Drop the army man from the top, recording the time. Then subtract the actual by the ideal, to get your controlled air resistence onlyThis is you controlled trial.

5. Measure a paper clip, and then add it to the man. Repeat step four. 6. Continue to add more paper clips, and continue doing step four until you have five trials.

__Data:__ Paper clip=.5g=.05kg Army man= 7.23g= .0073kg height=356.5 cm= 3.565 m Ideal Time: 0=33.565+0t+1/2 (-9.8)t^2 =.85 seconds
 * Trial || 1 || 2 || 3 || 4 ||
 * Time (sec) || 2.52 || 2.46 || 2.19 || 2.07 ||
 * Added || 0 || .001 || .002 || .003 ||
 * Total Weight (kg) || .0073 || .0083 || .0093 || .013 ||
 * Time of Air Resistance (sec) || 1.67 || 1.61 || 1.34 || 1.22 ||

__Conclusion:__ We can conclude that the time of air resistance varies inversely with the amount of weight put on the army man. By looking at our data table, one can see the added weight row and how the time changes when weight is added. By putting on more weight, we can conclude that the gravitational force becomes greater due to the multiplication of 9.81m/s^2, which is equal to the acceleration of gravity. From the Trials 1 and 2, one can see when the weight changes from 0.0073kg in Trial 1 to 0.0083kg in Trial 2. We can also see the time it takes for the army man to hit the ground declines from 2.52 seconds in Trial 1 to 2.46 seconds in Trial 2. Therefore affecting the Time of Air Resistance from 1.67 seconds in Trial 1 to 1.61 seconds in Trial 2. We believe this to be true because with a larger gravitational force, the force of air resistance decreases, thus the time of air resistance decreases. Though the evidence is in our favor, there are sources of error that make the evidence not fully valid. These sources of errors are human error, in which the stop watch may have not been pressed the exact time of the dropping of the army man. Another error is the error of rounding decimals, preventing us from getting an exact numerical error.