Group+6+Experimental

TITLE: How you survive a fall out of a tall building using household items as parachutes?

PURPOSE: To determine whether it is practical to jump off a building using sheets of fabric or possibly umbrellas found in home

HYPOTHESIS: Most likely not

RESEARCH/THEORY: To figure out whether it is possible to land safely using a sheet found in homes as a parachute, we are going to simulate a fall using toy human figured and 1m2 for each type of sheets that are commonly found. We have to measure the mass of the human figure, the area and material of the sheet, the height the human figure is dropped from, the terminal velocity, the final velocity, the time it took to travel, and the decelerating distance as the body is landing on the ground(by crouching down once feet hit the ground). Once the terminal speed is measured, the drag coefficient can be found by solving the equation also, **m** is indirectly proportional to **A** and all the other values are constant. This allow us to later on determine the necessary area of blanket need to land safely. The actual acceleration will be determined by finding the line of best fit for the v-t graph that is collected. Using the drag equation, we can then find the drag force applied due to air resistance on the sheet. From then on, the theoretical net acceleration can be calculated by subtracting the deceleration due to drag (a=F_d/m)from the acceleration due to gravity, so a_net=g - F/m. The theoretical results will just be used to compare. The actual acceleration will be used to calculate the time needed to achieve terminal velocity. To land safely on solid ground, the back of a human can withstand no more than 10g upright. Assuming the decreasing rate of the acceleration due to gravity throughout the fall is constant, the final g-force on the body is determined by the final velocity and the distance in which the central point of gravity of the body traveled. By using the distance the the central point of gravity traveled, we can calculate the deceleration (t=d/Vavg, a=V/t) - the g-force.

PROCEEDURE:
 * 1) Weigh the human figure and each piece of fabric (area of 1m2 each)
 * 2) Tie the fabric (sheet) to the human figure, achieving maximum expansion area.
 * 3) Measure the distance from which the human figure will be dropped from.
 * 4) Using a motion detector, measure the displacement, velocity, acceleration and time of the object dropping down. Terminal speed must be reached.
 * 5) Repeat step 3 for each kind of material and without.
 * 6) Let a human lie flat on a hard board, evenly spread out on it.
 * 7) Mount the board on a pipe which is placed flat on the ground and try to balance it horizontally and vertically
 * 8) Mark the location of the pipe each time, the point where the lines join is the central point of gravity
 * 9) Measure the distance between the central point of gravity of the same person standing upright and crouching as low as possible.
 * 10) Process data

OBSERVATIONS:

ANALYSIS:

RESULTS:

SOURCES OF ERROR:
 * The ends of the sheets that are tied to the figure changes the area by a little
 * The figure does not always drop vertically