Monday, January 12, 2009



Overall, this experiment is not quite a success as there are many factors that influence the error both in readings and apparatus set up. In order to reduce these errors, some consideration has to be taken to improve the experiment, so better performance can be obtained, hence making this experiment a success. In my opinion, the area where the lab is performed should be a closed set so that no blowing winds will affects the pendulum swing. Other than that, the set up for the experiment must be reliable and suitable apparatus must be used to improve the accuracy of readings taken, for example the usage of the ‘allen key’ as the hinge is totally unsuitable. Perhaps, more readings should be taken for each swings and then the average values are calculated, at least the values will not be so much in difference. Lastly, in this matter some errors can be eliminated if some precautions are taken seriously.   


Saturday, January 10, 2009



From the experiment, I found that there are several differences in between theoretical values and experimental values that being obtained. These differences should not be so obvious. The values supposed to be not much in difference as the experimental and theoretical values should be almost the same. By my inference, there are several factors that influenced these differences. One of the main factors that often occur in any experiment including this experiment is inconsistency while values are taken. Firstly, the hinge where the pendulum is hang is an ‘allen key’ and have 6 surfaces which is not smooth. Thus, the pendulum cannot swing smoothly compared if the hinge used is a smooth circular rod. While the pendulum is released, the angle where the pendulum is released is not accurate. The angle of released are not always the same each time, even the angle supposed to be at  since the measurement of the angle is only depended on the protactor which is hold next beside the pendulum. Moreover, the angle is observed with our eyes and at different position. Thus, accuracy in this matter is questionable. Other than that, the time taken for the pendulum swing is also questionable as it is observed also with our eyes. The point where the pendulum starts and ends after ten consecutive swings are not really exact as we cannot really measure when the pendulum change it direction to a reversed swing. The time taken when the pendulum completed ten swin9gs is also not accurate. Even this matter seemed to be unreliable, actually it affects our readings a lot when it comes to calculation. Besides that, the area where this experiment is held is close to the laboratory entrance door and wind is also the factor for the pendulum to swing inconsistently as the wind speed changes all the time. There are times when wind blows quite fast and there are times when no wind blows at all. Thus, all of the factors above do influence the readings taken throughout this experiment and that is why the results vary in some way.

Friday, January 9, 2009



For compound pendulum B,





 -------- (i)

           ---------- (ii)

Sub. (ii) into (i)

   ----------------- (iii)

 ---------------------- (iv)

Sub.(iii) into (iv)


Compound C:-




Compound A:-




Thursday, January 8, 2009



Pendulum swing



Smaller side at top, s


Reading, s

Larger side at top, s

Average reading, s

Rounded Rod








Rectangular Rod








Prismatic Thick Place









For Compound B (Rectangular Rod)




---------------- (i)

         ----------------- (ii)

Subs. (ii) into (i)

 ----------------- (iii)

     -------------- (iv)


Subst. (iii) into (iv)

Wednesday, January 7, 2009









When the connecting rod is suspended at A, the periodic time is given by:-




When the conrod is suspended at B, the periodic time is given by:-




At the same,total length between A and B is:-






It can be seen that in equation (i),(ii) and (iii) there are three unknowns, i.e. k,  and .Therefore, solving the three equations simultaneously, the three unknowns can be determined.