• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Introduction This experiment is about the effect of starting height on the speed of a ball bearing rolling down a slope.

Extracts from this document...

Introduction

Ben Karlin – 8119 / Wheatley Park School -62113

Physics Coursework – Ball Bearing Speed

Plan

Introduction This experiment is about the effect of starting height on the speed of a ball bearing rolling down a slope. By using simple apparatus, I will produce a set of results to show how fast the bearing will roll down the slope from a number of different starting heights.

Hypotheses The first hypothesis I will work from is that as the slope is always 50cm long, the higher the starting position of the bearing, the greater the gradient of the slope, so the faster the bearing will roll down it. If y is the length of the slope, 50cm, c is the intercept,which is 0, and x is the height, then the equation of a straight line is y=mx+c. To rearrange this in terms of m, m=(y-c)

                                                  x

Therefore the only variables in this equation are x and m,because the slope will always be 50cm long. In this way I can work out the gradient (m) of the slope each time I do the experiment.

The second hypothesis concerns the equation for potential energy. Potential energy is mgh, mass x gravity x height, taking gravity to be 10. Taking the weight of the ball bearing to be 1g, I can work out the relative p.e. of the bearing at each starting height. Kinetic energy is ½ms2, half mass x speed squared. When the height is doubled, the potential energy is also doubled because the other values, mass and gravity, remain constant.

...read more.

Middle

Height cm

Gradient

Relative Potential Energy J

Run 1 secs

Run 2 secs

Run 3 secs

Average secs

1.5

33.3

15

1.65

1.65

1.68

1.66

2

25

20

1.50

1.48

1.52

1.48

2.5

20

25

1.33

1.32

1.32

1.32

3

16.6

30

1.26

1.30

1.28

1.29

3.5

14.3

35

1.27

1.27

1.29

1.28

4

12.5

40

1.23

1.24

1.23

1.23

4.5

11.1

45

1.16

1.20

1.22

1.19

Analysis

I can identify a number of trends in my results. When height (and so potential energy) is halved, the time taken is, roughly speaking, squared. This supports the theory put forward in my hypothesis that since k.e. = ½ m/s2, and that if kinetic energy is relative to speed, it is therefore relative to time. This trend can be explained because of the way raising the height increases the potential energy of the ball bearing, thus meaning the speed is increased, and affecting the formula for kinetic energy.

The other trend in my results is also quadratic – when the gradient of the slope doubles, the time squares – this is the direct opposite of the trend relating to the height and the p.e. – a lower value for the gradient, in this case, means a steeper slope and a higher starting position, which means more potential energy and thus more kinetic energy and a faster time.

Having identified these trends, I will now draw a graph. I have decided to graph the time taken by the ball bearing against the relative potential energy it held at the start of the run. I will graph in this way as I feel this is the most relevant data and the easiest to talk about.

I will process my evidence by taking the average times from the three runs. I will do this because I feel that it will be the best way of displaying balanced and reliable results.

...read more.

Conclusion

Sufficiency of Evidence Given my evidence, it is likely that my conclusion is correct, as there are no results which truly contradict it. However, we have to accept that my results show a limited range of gradients of the slope, and that if the gradient was made much steeper, the times would be out of proportion with the formula, and that if it was made shallower, the ball bearing would not roll at all. Thus, though my evidence is indisputably sufficient to support my conclusion over the range of values for the potential energy of the ball bearing which I tested, the formulas the evidence conforms to is irrelevant to other values, so I cannot know how true my conclusion is in these values.

Further Work There is further, similar work I could do to help continue my investigations into this variable and help ascertain the verity of my prediction and conclusion.

I could use a metal ball, larger than a ball bearing, and a longer, smoothly polished wooden slope which I could quite easily construct myself. I would set up the slope against a meter rule placed vertically, so that I could easily vary and control the starting height. The slope would be longer and the whole experiment enlarged in this simple and practical way so that it would be much easier to time the experiments and eliminate human error to the greatest extent possible.

This further work would help me to answer the original question of how potential energy affects kinetic energy and speed, while increasing the ease of conducting the experiment by making the slope smooth and longer to reduce friction and variation, and to make it easier to take accurate measurements.

Ben Karlin 11SDB

...read more.

This student written piece of work is one of many that can be found in our GCSE Height and Weight of Pupils and other Mayfield High School investigations section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Height and Weight of Pupils and other Mayfield High School investigations essays

  1. Bouncing ball investigation.

    Section 3 Conclusion based on sec 1&2 The investigation was carried out quite well, and stayed true to the original method and ensuring that measurements were as accurate as possible; although one or two results may appear to be slightly anomalous.

  2. Maths Coursework Introduction

    Sampling Method: I will be collecting data from 56 students in year 8 but will altogether be stratified sampled as there will be a specific amount of girls and boys. There will be 28 boys and 28 girls. I have chosen 56 students so that there will not be too

  1. Practical Report: Drosophila BreedingAim In this practical experiment I will cross wild fruit flies ...

    Cross 3 Parent wild female � wild male Genotype XXBb XYBb Gametes XB Xb XB Xb XB Xb YB Yb F1 generation Male gametes XB Xb YB Yb XB XXBB Female wild XXBb Female wild XYBB Male wild XYBb Male wild Xb XXBb Female wild XXbb Female vestigial XYBb Male

  2. Investigate the stability of blocks by placing them on to a board and raising ...

    I will use the formula Sin-1 = O�H. E.g. I will use trigonometry to calculate the angle because it is more accurate than using a protractor. I will tip each block three times and then average out my results. This will reduce the chance of a large mistake or anomaly in my results.

  1. Determine the relationship between the range of the jump achieved by the ski jumper ...

    Then we placed the stool away from the edge of the table and it's indicated as "A" in the above diagram. 5. The value "A" depends upon dropping the ball at the lowest and highest height on the slope.

  2. Cause and Effect Essay - Cheating

    When the time comes that they will actually have to do the work themselves, they aren't going to have a clue on where to start. They won't know to take responsibility for the things they do and they will never be able to think something up on their own.

  1. Investigate the effect of temperature on the bounce height of a squash ball.

    Temperatures (�C) Difference in the bounce height (cm) 0-10 9.5 10-20 6.3 20-30 7.8 30-40 9.2 40-50 7.6 50-60 6 60-70 7 The biggest difference between the temperature's bounce heights is between 0�C and 10�C. 10�C is likely to be when the molecules of the gas inside the squash ball

  2. Does the height of a ball affect the diameter of the crater where it ...

    And by making sure that the sand remained still to stop the crater diameter from enlarging or decreasing. I took all my measurements in millimetre's to make then very accurate. On the back page there is a line graph of best fit to show my result averages.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work