• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11

Investigate the factors which affect the period of one swing (oscillation) of a simple pendulum.

Extracts from this document...



Aim: To investigate the factors which affect the period of one swing (oscillation) of a simple pendulum. The factors I will use are length of the string, and angle that the bob is released from.


1. Length of string

I think that the length of the string directly affects the period of one oscillation.  The mathematical formula used to describe the period of the pendulum is:

T= 2πimage02.png/g

T is the period (time for one swing - seconds)

image02.pngis the length of the pendulum (metres)

g is the acceleration dues to gravity. (N/KG)

image02.png (Length) is in the formula, clearly indicating that it is a factor which will directly affect the period of time.

To see whether the time period will increase or decrease when the length is increased, I will substitute the formula for numbers to see the result.

Length 0.3, g-force = 9.8N/KG

T= 2π √image02.png/g

T = 2π √0.3/9.8

T = 1.009s

Length 0.4, g-force = 9.8N/KG

T= 2π √image02.png/g

T = 2π √0.4/9.8

T = 1.269s

The calculations above show that when the length of the pendulum is 0.3m, the time for one oscillation is 1.009s.  When the length is increased, the time is increased.  When length is 0.4m, time period is 1.269s.

This tells us that when the length is increased, the time period is increased.

2. Angle of release

A simple pendulum is only a weight known as a “bob” hung from a string.  When the bob is lifted, the pendulum gains potential gravitational energy, as it is acting against the force.

...read more.


, (so, if the length of string was to be doubled, the period would be doubled as well).

The statement image02.png α T can be justified by taking values from the graph, for example when the length of the string is 5cm T= 0.481 and when the length is doubled to 10cm T= 0.651, which shows T is almost doubled.    

The table below shows actual results compared to the theoretical by working out the percentage error by this formula, percentage error= (actual error (actual result- theoretical results)/ exact value (theoretical results)) x 100:

Length of string (cm)

Theoretical prediction



Percentage error









































My average percentage error is 3.6% which suggests that our results are fairly accurate.

Experiment 2

By looking at the results obtained from my graph I found that the angle of amplitude did affect the period of oscillation, however in a very slow rate. Also I found some anomalous results in this experiment which could have been because we did not follow one of our control variables.

Experiment 3    

By looking at the table and graph obtained from my results I found that by increasing the mass of the bob had no effect to the period of one oscillation. This could be because that since the gravitational acceleration is 9.8N at all time (on Earth); the mass of the bob will have no deciding effect on the period of oscillation. The reason for this can be taken from my prediction, which is:



Height =image02.png - image02.png cos θ

...read more.


image02.png/g. Hence I will be able to work out the period (T) for the gravitational strength of each planet. To work out the theoretical prediction I must keep the length as a constant of 0.5m.
  • Theoretical Prediction


Gravitational Field Strength (N/Kg)

Time period (T) (s)




























Deep space




  • By looking at the table I can now base my results on a sound prediction and say that the stronger the gravitational field strength is of a planet the faster the time period is of one oscillation and the weaker the gravitational field strength the slower the time period of one oscillation.
  • I cannot continue this investigation, since my school does not have the resources for me to experiment on other planets.    

This controlled-falling system is a weight (bob) suspended by a string from a fixed point so that it can swing freely under the influence of gravity. If the bob is pushed or pulled sideways, it can't move just horizontally, but has to move on the circle whose radius is the length of the supporting string. It has to move upward from where it started as well as sideways. If the bob is now let go, it falls because gravity is pulling it back down. It can't fall straight down, but has to follow the circular path defined by its support. This is "controlled falling": the path is always the same, it can be reproduced time after time, and variations in the set-up can be used to test their effect on the falling behaviour.

...read more.

This student written piece of work is one of many that can be found in our GCSE Forces and Motion section.

Found what you're looking for?

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

Here's what a star student thought of this essay

3 star(s)

Response to the question

This is a good essay that ties experiment and theory together quite well. The student has answered the question of what factors affect the time period of an oscillation well. He has at first looked at his theory to determine ...

Read full review

Response to the question

This is a good essay that ties experiment and theory together quite well. The student has answered the question of what factors affect the time period of an oscillation well. He has at first looked at his theory to determine that length will likely determine the time period, and he has also used his initiative to think that angle and mass may affect the time period even though the theory says they do not. He has made a prediction based on his theory and on his intuition, however I would of recommended rather than just going on intuition he should of checked his theory to see what the theory predicts would happen in terms of increase in mass and increase in angle.

Level of analysis

The student clearly lays out his method which I would recommend always doing as it is best to know what you are doing before you do it, you don't want to be confused as to what to do when you get to the experiment. He calculates all his errors which is very helpful as it both adds depth to the coursework and helps to stop you from making incorrect conclusions, as you can see if the results could be due to errors. However he works out the error by comparing it to how the theory predicts the result should be, you should not do this. Make sure to calculate errors the regular way. He uses theory to calculate why the speed is not determined by the mass of the bob, which adds a lot of depth. However it could have been done easier by realise that the force is determined by the mass, but so is the acceleration, therefore since F=ma, since F is the mass multiplied by another value, you can put the equation as mk=ma, and the mas cancel. You could go into more depth and determine what determines k.

Quality of writing

The student's grammar and spelling is fine and so is his layout. However he should of made repeats and calculated an average to increase reliability, and he should of made a table for each of his experiments. He could of also plotted a graph to determine how his variables are proportional to each other.

Did you find this review helpful? Join our team of reviewers and help other students learn

Reviewed by jackhli 28/02/2012

Read less
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 Forces and Motion essays

  1. Marked by a teacher

    The Simple Pendulum Experiment

    4 star(s)

    When the person catches the ruler, we can read off the time that it took that person to catch the ruler, therefore determining the reaction time of the person. I will carry out this experiment 3 times and take an average of the results to determine my reaction speed.

  2. Marked by a teacher

    The purpose of this experiment is to see what factors affect the period of ...

    4 star(s)

    Keep the whole experiment in the same place so that the gravitational field strength does not change. To make this a safe experiment: 1. The clamp should stand secure same with the G-clamp. 2. Laboratory procedures should be followed.

  1. Determination of the acceleration due to gravity using a simple pendulum.

    Time20 = 0.5 + 0.005 = 0.505s -Absolute Error in Time2 = ((Absolute Error in Time20/20) x 2) / Value x 100% Percentage Error in Time2 = Absolute Error in Time2/Length x 100% Percentage Error in Gradient = Percentage Error in Time2 + Percentage Error in Length Percentage Error in

  2. An Experiment Using a Pendulum to Find the Acceleration due to Gravity.

    The reason my results will not necessarily come up with this exact figure is because there will be a degree of uncertainty. This will be due to the accuracy of my measuring ability, which will be controlled by the equipment I use and in some case my reaction time.

  1. Crater Experiment

    how big the crater can become this is clear from the graph because on both graphs there is a slight curve near to the end which I predict that will level off at some point due to the fact the it will not be able to gain anymore speed at some point onwards.

  2. Trolley Speed

    were printed there by a vibrating metal bar running on an electric current, which hits a piece of carbon paper 50 times every second. The analysis of a ticker tape diagram will also reveal if the object is moving with a constant velocity or accelerating.

  1. Physics investigation into the bending of a Cantilever.

    All other variables must therefore be kept constant in order to conduct a fair test and ensure results are accurate. ==> A variable such as l was not chosen as it has a more complex relationship with y and therefore if this were a variable there wouldn't be many results one could use, as y is proportional to l3.

  2. In this experiment I aim to find out how the force and mass affect ...

    Secondary Experiment-three tests on each 200g ) 400g ) 600g > Keeping height constant 800g ) 1000g ) Equipment Before we begin, we will need a list of equipment for the experiment to ensure it all runs smoothly: Trolley - To roll down the ramp Ramp - For the trolley to roll down Metre Stick - To measure out

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