Variables:
The 2 variables which can be altered during this experiment are: the radius of the string and/or the weight on the bottom of the string. For the experiment I have chosen to change the radius.
Method:
- Collect the equipment on the diagram shown below.
- Tie a loop on both ends of the string so that the bung and weights will stay firmly attached.
- Start circling the bung over the top of your head whilst holding the handle and weight, once you have got the right speed alter the radius so that it is correct, now let go of the mass and count 20 revolutions using the stop clock.
- The radius of the string should be at 10cm, 20cm, 30cm, 40cm, 50cm and 60cm.
- Do each different radius setting 3 times to make sure u have a fair result.
Conclusion:
We can conclude that as the radius of the string increases the speed of the bung also indefinitely increases. This is because it’s got a longer distance to travel in perhaps the same amount of time. From my observations I have noticed that the bung must be exerting some kind of force that lifts the weights. My experiment was a fair one over all except for a few minor occurrences which cannot be helped due to friction.
Evaluation:
I think that the procedure which I used was the best that I could have done, partly because the results I got were very good. On looking at my results I can tell that they are quite good because the line of best fit goes roughly through the top of all the results.
The method that I used was quite a reliable one and there were not very many problems that occurred from carrying out the experiment, the only slight improvement that I would do, which may not actually affect my results very much would be if, as I did, you took the readings in two different lessons and then used two different sets of weights, the weights may be slightly more or less and because we did not weigh them on the scales that cud affect the results and so the readings will be different, but as I said it may not affect the graphs too much.
Trying to keep the experiment a fair one was a tricky task. As me and my partner swung the bung over our head it was some times at an angle so the radius would be shorter. As you can see from the diagram below the lower dotted line and arrow are a smaller distance away from the centre which would have affected the results on at least more than one occasion.
