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

Investigate the oscillations of a simple Pendulum

Extracts from this document...


Experiment no. 1                                                            

Aim: -

To investigate the oscillations of a simple pendulum and find the value of ‘g’, acceleration due to gravity, in the laboratory.

Apparatus: -

                    Retort stand with clamp                                           Pendulum bob

                    Piece of thread (≈ 110 cm)                                       Stop watch

                    Two small wooden blocks                                       metre rule

Hypothesis and Theory:-

In this experiment the set up below is arranged. This is a simple pendulum system which is a simple harmonic motion. In the figure below consider a small mass m attached to the end of a length l of wire. The other end is attached to a fixed point P and the mass oscillates along the arc. Suppose the mass during the motion at a point B at an instant, such that OB = y (displacement) and the angle at that moment is θ to PO. The downward force by the mass is mg

...read more.



When θ is small then sin θ = θ in radians and θ= y/l (as the angle in a circle is equal to its radius multiplied by its arc.).

                                                               − mg θ = ma     (θ = y / l)

                                                               − mg (y/l) = ma

                                                                So, a= − (g/l) y

As the acceleration is directly proportional to the displacement so it is proven that the motion of a simple pendulum is simple harmonic.


g y =  w2 y


  Thus, w2 = g/l



     T=2πl/g           image17.png

So, while plotting a graph:-

T 2 = 2 ×l                    y = m ximage18.png


So, plot a graph of T 2 against l and the slope of the graph will be = (4π 2 /g)

Therefore g can be calculated.

The value of g will be approximately in this range:-

                              9.78 ≤  g  ≤9.88


The dependent variable is the time taken for the bob to complete one oscillation.

...read more.


The length of the thread must be measured from the point of suspension to the centre of gravity of the bob.Ignore the first few oscillations. One time steady oscillations.The angular displacement should not exceed 5˚.Avoid doing the experiment in front of the air conditioner.


Use varying masses or bob of different density that is of different variable. Calculating the value of  g with many variables will be more accurate than compared to using only one variable.


The hypothesis stated in the beginning is proven correct and the value of g, acceleration due to gravity, is obtained as 9.87 m s-2. This value is very correct as normally seen in this part of the world. The actual value of g is 9.8 m s -2, so the absolute and percentage error can be calculated.

Absolute error:

Absolute error = observed result – actual result

                        = 9.87 – 9.8

                        = 0.07

Relative error:


Relative error = image21.png


                       =   image23.png

                      = 0.00714

Percentage error:

Percentage error = relative error × 100

                           = 0.00714 × 100

                           = 0.714 %

...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)

    than my measured reaction time, or from a miscount in the amount of oscillations when recording 30 oscillations. One way of fixing this would to be to take more than one measurement of 30 oscillations, and then take an average of the results.

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

    The thread used was quite stretchy. If the investigation were to be repeated I would replace it with something more rigid, such as extra strong button thread. More repeats could be taken but I don't think this would add much to the accuracy of the conclusions.

  1. Period of Oscillation of a Simple Pendulum

    I said that mass should have no affect whatsoever on the rate of oscillation. It was possible to prove this from my results as I stated that if mass was to change, it would have no effect on the times.

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

    * The type of pendulum used in this experiment is a simple pendulum. The same pendulum will be used throughout the whole experiment, elimination any chance of the pendulum shape, structure or any other of its properties, being a variable in the experiment, therefore making it an unfair test.

  1. Physics Coursework: To investigate the Oscillations of a mass on a spring

    The effect of air resistance could be unimportant, but the energy loss from potential energy to heat energy could be from the air resistance. * The time (dependant variable) - The output variables will be the ones most affected by the mass on the spring.

  2. Studying a simple harmonic oscillator.

    Time t/s 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Velocity v/ cm/s -1.15 -2 -2.3 -2.6 -3.3 -3.7 -2.8 -2.5 -2.3 -1.45 -0.8 -0.55 Time t/s 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Acceleration a/ cm/s� -1.55 -1.43 -1.25 -0.95

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

    As it then rolls over the second set of electrodes, it again completes the circuit and stops the clock. Again I will take three readings, and in the end take the average. I already know the initial velocity to be zero, so using the final velocity and the time it

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

    The length is included in the formula, it will be one of the things used in calculating the acceleration due to gravity, and therefore needs to be measured as accurately as possible. The fishing line idea due to its clean crisp nature will have less friction at its pivot than the meccano idea.

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