The Constant “K” and “πr2” video gets academic reply -Dr. Richard Tia, KNUST

So yesterday I saw a video of a man ranting so furiously about the Ghanaian educational system and the “uselessness” of the things that are being taught in schools. He says that too many “foolish” things are taught in Ghanaian schools that have no use in life. He says he doesn’t see how “the constant k in variation” that he learned in school can get him kenkey to eat. He says he doesn’t see the usefulness of πr2 in the life of a human being for which school children should spend time learning. And he calls on the president Nana Akufo-Addo to change the syllabuses so that only “useful” things, things that have a bearing on the life of a human, are taught in schools.

At first glance, the video is nothing more than just a humorous piece meant to make people laugh and go on with their work, but if you see how extensively the video has been shared and the kinds of comments and support the video has received, you realize that a lot of people think like him, and you see the level of ignorance that has pervaded our system. In an era where people so often enjoy the comfort of opinion without the discomfort of thought, so much ignorance is spewed out there, which has the potential to subtly influence public thought and public policy.

The man shot the video in a nice car. I’m sure his day probably went like this: he got up and flicked on a switch and the lights came on. He switched on a radio or TV and watched a morning news or talk show. Then he ate a ball of kenkey, pressed his shirt with an electric pressing iron, jumped into his car and drove out. Then he took a camera and decided to shoot his rant.

What he probably doesn’t realize is that the electricity he uses is generated in the Akosombo Hydroelectric Dam.  The hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. The power extracted from the water is directly proportional (ie the variation the man says he sees no use of) to the difference in height between the source and the water’s outflow. That knowledge is crucial in the dam design.

The electrical energy is transmitted through several hundreds of miles to his home using copper wires – conductors – and not things like nylon ropes or pieces of wood because there is something called the Ohms Law which states that  the current through a material between two points is directly proportional to the voltage across the two points, the constant of proportionality being the Resistance, R. Based on the constant of proportionality R,  we are able to classify materials into insulators and conductors. That is why we know that we should use copper wires for the transmission and not nylon.

When he flicks on the switch and the light comes on it means someone has found a way to convert the electrical energy generated by the flow of electrons into light. When he uses the pressing iron, it means someone has a figured a way to convert the electrical energy generated by the flow of electrons into heat. And they are able to do that because they understand the physics of the conversion, which all depend on some complicated mathematics involving several variation constants.

Coming to his beloved kenkey, what he probably doesn’t know is that the kenkey comes from corn, which is produced with fertilizers. Most of the fertilizers come from ammonia which is made from the reaction of hydrogen and nitrogen gas. Simple chemical kinetics tells us that if we combine hydrogen and nitrogen gas and leave them sitting at room temperature almost nothing happens and (almost) no ammonia is formed.

However, in the presence of finely divided iron in what is called the Haber-Bosch process, the reaction is very feasible and ammonia is produced. The iron acts a heterogeneous (i.e. surface) catalyst – the gases are adsorbed on the surface of the iron, followed by bond activation and bond dissociation and the subsequent reactions to form the ammonia. The rate of the reaction is proportional to the fraction of surface covered by the hydrogen and nitrogen gases, which is turn is proportional to the pressure of the gases.

Read also: The Trump Era And The Ghanaian Dream

Through this complicated series of mathematical derivations, we arrive at what is called the Langmuir-Hinshelwood and the Eley-Rideal mechanisms for surface-catalyzed reactions, which we use to optimize the production of ammonia for the making of fertilizers for the growing of corn for the making of kenkey.

I could do the same analysis with every facet of his life, to demonstrate to him and all those who think like him the usefulness of the “constant k in variation” and πr2 in our daily lives.

The fact is that there are too many ignorant but opinionated people walking around, who talk about things they don’t understand. Any student who listens to them and neglects their studies does so at their own peril.

Facebook Comments


  1. Well written Doc. Whatever we have in our syllables here in Ghana gives the foundation of what we become in future professionally. It also enriches our knowledge and broadens our horizon as people. I found the video to be a comic relief in a stressed environment and nothing more. So i will implore all students to take every subject taught in school very seriously. Branding a subject as useless is detrimental to your future because running on knowledge, the world is constantly changing and you’d not want to be left behind

  2. Thanks a lot Dr. Richard Tia. If we had many of your type in Ghana civilisation through Science would have jumped to the next level in Ghana.

Leave a comment