• 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
  12. 12
  13. 13
  14. 14

Simple Harmonic Motion.

Extracts from this document...


Physics Practical Report                

Title:        Simple Harmonic Motion

Objective:        To examine the characteristics of the motion of a simple pendulum and measure the gravitational acceleration g.

Apparatus:        One approximately 0.5 kg mass, one G-clamp, one long string, one ticker-timer, one roll of ticker tape, one low voltage power supply, one stand and clamp, two chairs, one stop watch.


In a simple harmonic motion, it is defined that image00.png.

The displacement is defined as image01.png, where A is the amplitude, image10.png is the angular velocity and t is time of the motion.





Hence, when x is at equilibrium position, a must be zero.

In a simple pendulum,

F        =  mgsinθ

ma        =  mgsinθ

a        =  gsinθ

If θ is very small, sinθ = θ when measured in radian.

a        ≈  gsinθ

                        =  (-g)(image44.png)

image02.pngimage03.png  and  image04.png



Hence, the slope found is –image08.png.




image05.png The slope of a T-image12.pnggraph is image13.png.


We have set up a simple pendulum by using an approximately 0.5kg mass, a G-clamp, one chair, a string and a stand and clamp as follow:


We then set the pendulum into motion with different lengths l of string and use a stop watch to record the period (T). 10 periods (10T) of the motion is recorded for each length of string (l).


...read more.



image05.png The slope of the best fit = image25.png.

The theoretical slope = image26.png.

Hence, the experiment is done quite accurately.


We have then modified the simple pendulum a little by connecting it with a ticker-timer system to record the motion of the simple pendulum as shown below:


With the attachment of a ticker-tape, we set the mass at rest in the vertical position and mark down the equilibrium position on the tape. We then pull the mass to the right. After that, we turn on the power supply and allow the ticker-timer to take position-time record on ticker tape. We then immediately release the mass and allow it to swing to left. When the mass was completely swung to the left, we turned off the power supply to prevent any unwanted tick on the ticker tape.


image02.png        The frequency of the ticker-timer is 50Hz.

T  = image27.png

image05.png        The time interval between two successive dots        = image28.png

= 0.02s

It is obvious to see that the separation between two successive dots before reaching the equilibrium position increases but decreases after reaching the equilibrium position.

Take the direction to the right is positive.

At t = 0, the displacement is maximum, the velocity is zero and the acceleration is negatively maximum.

...read more.


Moreover, we observed that the mass would rotate a little itself. This error is very difficult to prevent from unless an extremely care is paid when performing the experiment. Again, some energy may be converted from translational energy to rotational energy. Hence, the speed would be slower.

One more error is the air resistance. There may be damping forced added onto the system. This may reduce the speed of the mass.


The clamp should not oscillate despite the fact that the arm of the stand is not strictly held on the base.

The whole stand and clamp should be held firmly by G-clamp.

The angle of oscillation should be small. Otherwise, the assumption does not hold.

The equilibrium position should be marked accurately so that the period is correct.

The mass should be released skillfully so that the mass does not move in an ellipse form and does not move circularly itself.


...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

    Experiment Report: Studying a simple harmonic oscillator.

    3 star(s)

    The corresponding displacement was also found. 9. A displacement-acceleration (x-a) graph was plotted. 10. The graph was commented in the following part of this report. Result Displacement x / m 12.6 11.6 10.8 8.8 6.5 3.7 0.7 -2.4 -5.2 -8 -9.8 -11.2 -12.2 Time t /s 0 0.1 0.2 0.3

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

    as it falls. By tradition, this is the method we have commonly ascribed to Galileo Galilei. In this experiment, Galileo is supposed to have dropped objects of varying mass from the leaning tower of Pisa and found that the gravitational acceleration an object undergoes is independent of its mass.

  1. Period of Oscillation of a Simple Pendulum

    However, this pattern did not emerge until after 40�. This indicates that if air resistance was the main contributing factor, then there must be a critical speed for it to reach before it will be affected by air resistance enough. The results before this virtually remained the same and alter from both positive to negative at all ends of the scale between 0� and 40�.

  2. Ticker Tape

    The area occupied by the box may also have served as a clear area where your feet should stay away from. It also functions as a target, so it is clear to you and everyone else where your weight will be falling and they will stay away from there.

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

    The time will then be divided by the number of oscillations to give the period, which is how long it takes for the simple pendulum to complete one oscillation. It is important to calculate the period this way, rather than just time one oscillation because as Roger Muncaster explains, "the

  2. Lab Report on Acceleration

    calculate the acceleration we will need to use the following equation for motion: The next step is to make a (acceleration) the subject of the equation This means that, where v is final velocity, u is initial velocity, and s is the distance traveled which is a fixed value of

  1. Strength of a string practical investigation

    * Extension: This will change as more masses are added to the string, I will be collecting readings of extension changes until the string snaps. * Force (via. Masses): This variable will be controlled by me, I will add masses to the strings until they snap.

  2. Studying a simple harmonic oscillator.

    Time interval between successful dots = 0.02 second. 5. These data was plotted on a displacement-time graph (on Page 3 ). 6. The velocity was worked out from the slopes of the curve in the displacement-time graph. The velocity-time graph was plotted (on Page 4 ).

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