= m v2 / r
Where v and m are the object's speed and mass, respectively. The radius of the orbit r is the same as the distance between the moving object and the central body.
Here is a diagram that I drew explaining how the centripetal force of a object like a ball works.
There are three possible factors or variables that can affect the force. There is the weight put on the nylon wire also known as the tension applied. There is the diameter of the nylon wire and there is the weight of the bung.
To decide which variable I was going to test I did some preliminary work. This would help me see what variable was the ideal one to use and what ranges I was going to use for the investigation.
Preliminary Work:
Method:
- A rubber bung was taken; a hole was then drilled into it.
- A nylon line fed through the middle part of the hole. The centre of gravity of the bung was then obtained by finding the centre of the bung’s length and its breadth.
- The nylon line is to be fed through the plastic tube. The length between the tip of the plastic tube and the centre of gravity of the bung was set to the lengths specified in the range selection, and a knot tied at that point.
- Also a crocodile clip was placed to ensure that the wire stayed in one place. Once done, place weights on the wire, because I was going to investigate the radius I had kept the weight constant a 200g.
- Now swing the bung and time how long it takes to complete 20 revolutions. Record results on a results table. Repeat for precision. This is because if you have a multiple set of results, you can also cross-refer with them, and can interpret which set of results are more reliable.
We had to use certain apparatus for this experiment; it is all listed below in the apparatus list.
Safety:
- Wear safety goggles, otherwise the bung can take ones eye out.
To Ensure a Fair Test:
- Make sure that the diameter of the fishing wire is constantly 63mm.
- Place the right weights on the fishing wire, to add up correctly.
- Make accurate calculations to at least 2 decimal places.
Apparatus List
- Ruler
- Bung
- 50 gram weights
- Fishing Wire
- Plastic Tube
- Timer
- Crocodile Clips.
Diagram:
Results from Preliminary Work
From the experiment I can say that I am going to investigate measuring different size radii.
Here are my results.
I repeated the experiment to get accurate results.
I have learnt that the range I have used Is good and I will use that for the plan. The preliminary experiment proved to be successful. This is clearly supported by the fact that the results obtained were very similar to one another, indicating the fact that they are also reliable.
Ranges:
The other two factors:
Keep the weight at 200g and the mass of the bung the same.
Final Method:
Method:
- A rubber bung was taken; a hole was then drilled into it.
- A nylon line fed through the middle part of the hole. The centre of gravity of the bung was then obtained by finding the centre of the bung’s length and its breadth.
- The nylon line is to be fed through the plastic tube. The length between the tip of the plastic tube and the centre of gravity of the bung was set to the lengths specified in the range selection, and a knot tied at that point.
- Also a crocodile clip was placed to ensure that the wire stayed in one place. Once done, place weights on the wire, because I was going to investigate the radius I had kept the weight constant a 200g.
- Now swing the bung and time how long it takes to complete 20 revolutions. Record results on a results table. Repeat for precision. This is because if you have a multiple set of results, you can also cross-refer with them, and can interpret which set of results are more reliable.
We had to use certain apparatus for this experiment; it is all listed below in the apparatus list.
Safety:
- Wear safety goggles, otherwise the bung can take ones eye out.
To Ensure a Fair Test:
- Make sure that the diameter of the fishing wire is constantly 63mm.
- Place the right weights on the fishing wire, to add up correctly.
- Make accurate calculations to at least 2 decimal places.
Apparatus List
- Ruler
- Bung
- 50 gram weights
- Fishing Wire
- Plastic Tube
- Timer
- Crocodile Clips.
Diagram:
Prediction: I have learnt that as the radius of the thread increases the speed or time that is taken for the bung to move in 20 revolutions is faster than that with a smaller radius.
