Controlled Variable:
A control of this experiment would be having the drop height the same throughout the experiment. This will be measured by using a meter stick and marking the height at which to drop the paper helicopter. The paper helicopter will drop at that marked height each time. Another control of this experiment would be having the same person timing the experiment for every trial. To keep the data as consistent as possible, the experiment will be using the same stopwatch, electric scale and paper helicopter each time. Another control would be using 5 paperclips of each with a mass of .7g (±.1g). Measure each paperclip by placing them (on at a time) onto the electric scale and record.
Apparatus and Materials:
1. Printer paper
2. Scissors
3. Meter stick ± .01 cm
4. Five paper clips: .7g each (±.1g)
5. Stop watch: (MyChron ± .01 s)
6. Electric scale: ± .1 g
7. Pencil
Procedure:
- Obtain a piece of printer paper and use a pencil to draw a helicopter shape (see figure 1 below). Cut out the shape and fold back the wings of the helicopter along the dotted lines.
- Mass the completed paper helicopter and record.
- Obtain 5 paperclips of the same mass, each weighing .7g (±.1g) each.
- Use a meter stick (± .01 cm) to measure the distance from the ground to a height of 1.00 meter. Mark the distance. This will be the drop height.
- Clip one paperclip onto the top of the paper helicopter and place the top of the helicopter from the drop height. Time from when the hand lets go of the paper helicopter till when it reaches the floor. Record and repeat four more times.
- Repeat step 5 with 2 paperclips, 3 paperclips, 4 paperclips, and 5 paperclips respectively and record.
Figure 1: not drawn to scale
Data collection and processing
Data Table:
Data processing:
Average Time (s) when the mass of paper helicopter is 1g
(.61g + .65g + .63g + .63g + .62g) / 5 = .63s
Uncertainty for when mass of paper helicopter 1 g
.65s -.61s= .04s / 2 = .02 s
Minimum slope:
.63s-.02s= .65s
1.0g +.1g= 1.1 g
Maximum slope:
Graph:
Conclusion and Evaluation
Conclusion:
Based on the data collected, the hypothesis is accepted because as the mass of the paper helicopter increases, the average drop time decreases. This is evident in the data collected because the paper helicopter with a mass of 1g (±.1g) had the highest average drop time of(63 ± .02s) while the paper helicopter with a mass of 3.8g (±.1g) had the lowest average drop time of (.40 ± .06s). This is due to Newton’s first and second law. Newton’s laws states that an object will accelerate if the forces acting upon it are unbalanced and the amount of acceleration is directly proportional to the amount of net force acting upon it. Falling objects initially accelerate because there is no force big enough to balance the downward force of gravity so the object will continue to accelerate until the air resistance force increases to a large enough value to balance the downward force of gravity. Thus the objects (in this case paper helicopter) with a greater mass will continue to accelerate for a longer period of time then a paper helicopter with a lower mass which thus results in a decrease in drop time.
Weaknesses and Limitations:
One of the biggest weaknesses in this experiment was the human error with the reaction time when starting and stopping the stop watch. It is impossible to correctly start and stop the stop watch when the paper helicopter drops because of human reaction time (time needs to pass before the thought from the brain reaches the hand to start and stop the stopwatch). This serves as a limitation because although the stop watch was controlled by the same person each time, a different time lapse will pass each time thus causing the inability to accurately time the helicopter drop each time. Another weakness would be that since the person holding the paper helicopter each time has to move their hands, the angle at which the paper helicopter is dropped won’t be the same each time which results in a shorter or longer drop time if the paper helicopter lands closer or farther from where it was dropped.
Investigation Improvements:
There are several ways to improve this investigation to make the data more accurate. To decrease the lapse in stopping the stop watch, using a higher drop height would give the person timing more time to react to when the paper helicopter reaches the floor because the original procedure allowed (at max) 65 seconds to react from the time it took the paper helicopter to drop from the drop height to the floor. Another way to improve this investigation would be to create a stand that will hold the paper helicopter at the same drop height and angle each time so that the distance that the paper helicopter will land will be the same each time. This will reduce the error in time because of a shorter or longer landing distance.