- Level: International Baccalaureate
- Subject: Physics
- Word count: 1594
Determining how the height of release affects the velocity of a basketball
Extracts from this document...
Introduction
Akash Singh 2/15/2011
Physics SL Mrs. Trumic
Determining how the height of release affects the velocity of a basketball
Introduction: Velocity can be measured by the formulae of displacement over time. In this experiment we shall see how different heights of release for a basketball, can affect velocity.
Aim: This experiment is directed in the process of discovering how the changes in the variable of height can have an effect on the velocity of a basketball.
Apparatus:
- 1 Basketball
- 1 Tape ruler
- 2 Stop-watches
- 1 hard flat surfaced object
- Writing instruments
Variables
Independent Variable: Is the height from which the ball is released. We shall perform the experiment in this order of 4 measurements: 30, 60, 90, 120 and 150 cm’s.
Dependent Variable: is relied upon changes from the independent variable, and therefore we can identify it as time. The time it takes for the basketball to hit the ground after release, will change due to changes in the height.
Controlled Variable:
- The same person releasing the ball
- Air pressure and wind in the room, so it doesn’t affect the aerodynamics
- The angle from which the ball is released
- The basketball: so the mass and dynamics of the ball are the same
- The same person calculating time with the stopwatch
Method
- On a straight wall, use the tape ruler, to mark the following heights of release: 30, 60, 90, 120, 150 cm’s with a marker.
Middle
Average Time (seconds)
1st trial
2nd trial
3rd trial
30
37
25.5
22
28.2 ± 9.0
60
45
29
37
36 ± 17.0
90
69
37
37
46.7 ± 15.0
120
144
29
66
54.8 ± 2.0
150
52
64
58
56.7 ± 7.0
Calculations
All figures with more than 3 decimal places are shown to a smaller degree but the memory of calculator was used in calculations for the sake of accuracy.
Here I will show the workings for the processed data summarized in the previous table.
To find the average time:
Sum of readings / no. of readings
Example
To find the average time from a release of 30 cm. You take the sum of the readings, which are the results from trials 1, 2, 3; which gives (37+25.5+22) / 3 = 28.2 seconds.
In order to find the uncertainty for the average time we have to use the following process: You take the average time and then you subtract it by the highest time. Additionally you take the average time and subtract it to the lowest time. You take the highest difference in the results and you add that to the uncertainty of the stopwatch which is 0.0005seconds.
Example
Average: 28.2
Higher Uncertainty = 28.2 – 37 = 8.8
Lower Uncertainty = 28.2 – 22 = 6.2
Uncertainty for time of 30 cm’s = 8.8 + 0.0005 = 8.8005
= 9.0 seconds (1.s.f.)
The next step is to calculate the velocity, which can be found by 2 methods. Graphically or using the formula of velocity. We shall first analyze the graphical method:
Graph
Is attached at the back of the lab report.
Conclusion
To improve I could maybe get two laser gateways, which self time using a computer, when the basketball is released and when it impacts the ground. This is a much more accurate result.
Due to this large uncertainty because of the synchronization, we should’ve also taken a larger number of data so we could have a more accurate overall average. And maybe, more people doing the stop-watch simultaneously which will allow us a more accurate reading.
Additionally there may also have been parallax error, caused when the ball has to be fixed to the wall at the x height. It may have been not precise.
To improve we could get a flat surface and place it exactly at the height. And then place the ball above it. And when you remove it, the ball falls, pentrating the laser and starting of the counter. Giving is us all in all much more accurate results. Although, this may be expensive to encourage.
This student written piece of work is one of many that can be found in our International Baccalaureate Physics section.
Found what you're looking for?
- Start learning 29% faster today
- 150,000+ documents available
- Just £6.99 a month