"a caterpillar doesn't just grow into a butterfly. a caterpillar must undergo metamorphosis, and a cocoon is where a caterpillar risks it all: enters total chaos, undergoes total rebuilding, and is born to a new way of living. only in taking the risk of entering that inert cocoon can the caterpillar go from dormancy to potency, from ugliness to beauty."

Saturday, August 28, 2004

a coconut story and some physics

"It is the mark of an educated mind to be able to entertain a thought without accepting it." -- Aristotle

i hope reading this entry does not give you a headache. if it does, let me know.

jerk, a good friend and former college classmate, informed me about this: about two weeks ago, a coconut fruit (which i will simply refer to as coconut in the succeeding paragraphs) accidentally fell on the head of my bubbly friend, naomi.

i don't know how heavy the coconut was, but naomi gave jerk the estimated height from which it fell: 5 to 6 meters. so, we have an idea of some things...

assuming that the coconut fell straight down and that air resistance is negligible, and knowing naomi's height to be about 5 feet and 3 inches (about 1.6 meters), the speed with which the coconut hit her head was about 9 meters per second, which is about thrice as fast as a car traveling at 10 kph.

if we make an estimate of the coconut's mass, say 150 grams (too light!), we can also have an idea of the kinetic energy of the coconut just before it hit naomi's head: about 6 joules, which, by the way, would have also been the work done by the coconut on naomi's head. if the coconut were heavier, say 750 grams, the value would be about 30 joules. if the coconut had a mass of 1 kilogram, then the value would be about 40.5 joules.

just before impact, the coconut's momentum is about 1.35 kilograms-meter per second if its mass was 150 grams, 6.75 kilograms-meter per second if it's 750 grams, and 9 kilogram-meter per second if it's 1 kilogram. since the coconut fell from rest, the value of the momentum just before it hit naomi's head would have also been the impulse of the force that caused naomi's head to hurt.

problem is, i honestly don't have a reliable estimate of the coconut's mass... which is, for this case, just okay.

truth is, one need not worry too much about those quantities i mentioned above. naomi is okay. cool gal that she is, naomi, despite having an aching head for three straight days due to the coconut blow, took the accident lightly and even laughed about it. the last i heard, she didn't go to the doctor to have her head checked. tough girl!


you know what i realized? we often qualify rather than quantify... and that's just okay.


  1. my head's spinning... anybody have some advil...?

    originally posted on 08.29.04 - 3:27 am using Haloscan comment board

  2. hahaha :D...but then that headache is better and safer than the "coconut" headache.

    originally posted on 08.29.04 - 10:22 am using Haloscan comment board

  3. si naomi, gahi gyud ug ulo...hahahahaha

    originally posted on 08.29.04 - 4:19 pm using Haloscan comment board

  4. that sure gave me a headache! not because of the fact that naomi is a good friend, but because of all those calculations!

    shucks! if something fell on my head, please do NOT calculate, okay? hehehe

    originally posted on 08.30.04 - 5:10 am using Haloscan comment board

  5. i (actually, we) ended up calculating when naomi couldn't be convinced to see a doctor. i somehow began wondering about the impact and all, and jerk jumped right in.

    originally posted on 08.30.04 - 11:13 am using Haloscan comment board

  6. right! qualify rather than quantify always. mao kana ang wala kaayu na-emphasize nga attitude sa current approach sa physics education. sa current physics education man gud, we always solve numerical values. ang tendency sa student kay ma-misled sa panghunahuna nga pwede mameasure EXACTLY ang tanang butang. that's why we can hear statements like "dapat maayu ka mu-shoot sa basketball kay physicist gud ka, projectile man na" which is not true. well, kabalo na man tingali ka ani. (gapagawas lang sa gibati).

    originally posted on 09.05.04 - 3:38 pm using Haloscan comment board

  7. mao. abi nila importante jud kaayo ang numerical values... bisan mas importante masabtan ang unsa, ngano & giunsa. thanks for elaborating on a thing which i failed to share.

    originally posted on 09.06.04 - 2:40 am using Haloscan comment board


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