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

Measuring Acceleration due to Gravity using a simple Pendulum.

Extracts from this document...

Introduction

Measuring Acceleration due to Gravity using a simple Pendulum


Simple Harmonic Motion is very similar to the motion of a bob of a simple pendulum. A simple pendulum is made of a metallic bob suspended by fine string. Using these apparatus the acceleration due to gravity had to be measured. The acceleration due to gravity on earth is 9.81ms-2, therefore every second the particle will increase it’s speed by 9.81ms-1. Although, this may not be the case, due to air resistance.

Acceleration is directly proportional to force and acts towards a fixed position.


Planning


To derive a value for g, the S.H.M. equation was used:

image01.png

For calculating ‘g’ the formula had to be rearranged:

T2 = 4π2l

         g

Therefore:

g = 4π2 l

         T2

Where: g is the acceleration to gravity; T is the period & l is the length.

Out of the above, the length of the pendulum had to be measured and then the period with that information. Instead of using the formula, a graph could be drawn of length against T
2, calculate the gradient, invert it then multiply by 4π

g =
4π2 l

         T2


“”””“””””..

...read more.

Middle

1.200

47.49

2.38

1.000

44.09

2.21

0.800

40.10

2.01

0.600

35.19

1.18

0.400

29.20

1.46

0.200

21.11

1.06

With the preliminary experiment there was only a need to include one set of results, but in the final experiment three sets of results will be collected for more accuracy. A problem rose whilst trying to measure the length of the pendulum. It was unknown whether to measure the whole length of the bob, only to the top of the bob or to the middle of the bob. A final decision was made to measure to the middle of the bob, as this is where an assumption can be made that all the weight acts in the centre. This is why the bob being small and dense was made important. A piece of string was used in the preliminary experiment although this would carry extra weight compared to a piece of cotton. By using cotton the overall weight of the pendulum was reduced. A stopwatch was used to measure the swinging motion but this may have led to random errors.

Fair Test

To make the experiment as fair as possible the same bob and equipment were used for each experiment.

...read more.

Conclusion

th of a second. If stopwatches were used which were more accurate, i.e. 1000th of a second a more precise result could have been gained.

Resolutions:

Resolution

Length (m)

0.001

Time (secs)

0.01

Improvements

To improve the experiement:

* Light gate :

  1. You can use a Distance Sensor Metre; you will use this by using the pendulum except you will swing the bob back and forth towards and away from the DSM. The DSM will be linked to a computer and by using a certain program you are able to produce a graph of the information collected. From the graph you can work out a value for ‘g’.

  2. You can also use a light gate, by doing this you will put a light gate about halfway across the pendulum. You will then use a computer program to measure the time it takes for the pendulum to cut the light gate twice. You will have to times the time by two; this will then give you the period for the pendulum.

Accuracy improvements

For an improvement of accuracy:

  • More repeat readings; this will cancel out any anomalous results.

  • Equipment; could have used equipment of more accuracy, i.e. a computer programme & light gates

...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

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)

    2.17 120 67.9 67.5 2.25 130 69.1 68.7 2.29 140 71.5 71.1 2.37 150 73.9 73.5 2.45 Mass = 35 grams L = Length of Pendulum's swing A = Time for 30 oscillations R = Reaction Time T = Time for one oscillation Mass Experiment results Mass (g) A (s)

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

    Each measurement is has an absolute error of ?0.5mm as each measurement is given to the nearest mm. This error should be doubled, as there will be an error on each side of the metre ruler. * Measurement of time: Human error as well as reaction times can make a large contribution to any errors in the experiment.

  1. Determining the acceleration due to gravity by using simple pendulum.

    Variables Length The length of the pendulum has a large effect on the time for a complete swing. As the pendulum gets longer the time increases. size of swing Surprisingly, the size of the swing does not have much effect on the time per swing.

  2. Investigating the period of a simple pendulum and measuring acceleration due to gravity.

    Period equation: T = 2? L g Straight line equation: y = mx + c. T = 2? L g T� = 4?� � L g T� = 4?� L g y = mx + c A graph between T� and L can be drawn.

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

    The only factors left are the variables I will be experimenting with in this investigation ? Primary Experiment - I will be investigating, by varying the height the summit of the ramp is raised off the ground, if the average speed increases or decreases.

  2. The determination of the acceleration due to gravity at the surface of the earth, ...

    The period of oscillation of a pendulum depends on three factors: 1. length of pendulum 2. amplitude of displacement 3. acceleration due to gravity The gravitational field strength of earth varies slightly depending on where you are. However, the experiment is being conducted in the same place and so this will have no affect as a variable.

  1. Carry out an experiment of simple harmonic motion using a simple pendulum and determine ...

    axis - length (L/m( An extra column will be needed in the results for the values of (L as the graph will be time against length. The gradient of the graph can be used in the time period equation to find the acceleration due to gravity.

  2. Determining Gravity with a Pendulum

    Tie one end of the strong string onto the center of the pendulum and the other end of the string onto the pivot point (end of the whiteboard diagram hanger), while making sure that the actual length from the pivot point to the center of the pendulum is 90cm.

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