My explanation. Very nerdy piece coming up, beware.

 

There is inconsistent percentage error in all the graphs. From the graphs, the value of g calculated is more or less than its original value, but never exact. This is due to many uncontrollable external factors such as air friction and air movement, as well as systematic and random errors. As the values obtained will inevitably affect the best line plotted, the accuracy of the values is integral in deriving the most accurate g value.

 

Due to air resistance, the gradient of the graph is actually steeper than the actual gradient required to acquire the exact value of gravitational force, that is 9.807 ms^-2. As the gradient value increases, the g value decreases according to the formula. Theoretically speaking, the value that we obtain from the graphs should be smaller than the actual value. However, there are other factors to be taken into account, hence the possibility of calculating a value which is higher than the actual value from the graphs.

 

One possible conjecture for the percentage error is that the angles for all lengths were inconsistent as there was no way of fixing the angle before displacing the pendulum. The angle of displacement can affect the consistency and accuracy of the time taken, which in turn affects the values plotted on the graph and eventually influences the gradient of the best line. Besides, the absence of wooden blocks to clamp the pendulum string also affects the readings. Without the wooden blocks, the string of the pendulum is prone to collide with the retort stand clamp, further deviating the accuracy of the readings obtained.

 

Another systematic error to be taken into account is the stability of the retort stand. As the pendulum oscillates, the retort stand clamp tends to wobble a bit as it is attached to the pendulum. Zero errors due to the faded markings on the metre rule might also be faulted for inaccurate measurements of the string, overall affecting the corresponding T value. ( Metre rules/calculators were created by humans too. The markings/answers might not be accurate, you never know.)

 

Random errors include lack of sensitivity due to human limitations of sight and touch and natural errors such as changes in air movement (yes, we breathe) during the experiment. These errors are beyond our control, and have to be taken into account. (Oh, and the rulers we use might be bent, so the line comes out slightly curved.)

 

As such, there can be no accurate reading, and hence the percentage error will exist always. The line of the best fit is not independent of each and every value, so in the event the g value obtained from the gradient is bigger than the actual value, blame it on the corrupted values obtained. 

 

I am so brilliant at making excuses. *whistles* It's either that, or change all the values and replot the four graphs.

 

Dream on.

This year, my classmates seem to be really hyped about one particular topic : Sexual drives.

 

Or maybe they've been hyped up about it since dinosaurs roamed the earth, but it just stands out now in frequency. =P That's where the fun of being in a co-ed school really hits you - the guys and girls have no qualms about discussing such issues. =) And don't ask me why I took so long to join in those discussions - I just never felt the urge (pun intended) to find out more until now.

 

I think I'd better be more honest here. =P In actual fact, conversations revolving around such issues garner the most interest from fellow classmates. The guys will, predictably, make cheeky and oftentimes obnoxious comments, while the girls will roll their eyes and set them straight. When all else fails, we also tend to resort to feminine wiles and mental-image-painting to shut them up. Guys can be so hopelessly driven by primal instincts. xD

 

The beauty of free periods? Lol.

 

On better days, members of both genders actually get to learn more about the mysterious ways of the opposite sex.

 

'You don't understand. We guys are hypersensitive to anything related to sex.'

'Girls get aroused too, but more often because of excessive touching.'

'I don't understand. If you girls have vaginal discharge daily, doesn't that mean you're perpetually wet down there?'

'There are many types of sanitary pads/bras.'

'So what arouses a guy? Say, if a girl touches you here...'

'What do you mean, 'reluctant'? We're only reluctant to stop satisfying our urges.'

 

And the very famous line : 'Eee, how on earth do/would you know?'

 

Works every time to send the guys off into fits of nervous chuckles/defensive arguments.

 

That's just the tip of the iceberg. You can just imagine how attentive, albeit rowdy we all are while learning about contraceptive devices during Biology. An outsider looking in may wonder at our open-ness (some might even consider it perversion), but I actually consider it healthy to learn more about the opposite sex in a natural setting. It's an eye-opening experience.

 

Kinda makes you wonder if "hiaw" should be redefined, doesn't it? =)

 

[Author's disclaimer : I am not perverted. I join in those discussions purely for the sake of gaining extra sociological/psychological insight.]

 

...I mean it. xD

We made soap during Chem period today.

 

Reminds me of how grateful Jia Wern is for his soap.

 

*mutters* He'd better be.

 

Another random fact : The only reason I eat guava is because of the semboi powder (sour plum powder)that comes with it. It's wonderful how tasteless guava is so I can imagine myself sucking on a sour plum instead. Yummy. I don't know why I have a penchant for sweet and sour flavours. My mouth is watering already at the mention of sour plums. Junk food, my achilles heel. *sigh*

 

Without the sour plum powder, guava is tasteless as a rock. =P I don't eat rocks, do you? I only eat sand and grass. Yummy.