[S3 Physics and up: Pressure] Kept you waiting, huh? Whistles, and the physical process of whistling for most of these tools, is caused by changing the way the air vibrates within its cavity. To explain a bit more on the topic, the second hole before the first for the kettle has a set distance between each other, and it helps to resonate wavelengths at that distance to make it louder. Much like how light at different wavelengths look different, sounds at different wavelengths
[S1 Science: Convection] If you're wondering what it's like for your poop to be managed in Singapore, yes, we use a similar system to the one described: Our water reclamation plants use a system similar to the one mentioned, where we treat the sewage and recycle the water that came with it. The warning signs as shown shows us how science can inform us of the dangers within the workplace. Do be careful the next time you visit a large body of water.
[P5/6 Maths: Part-Whole Relationships] Here's a quick teaser: Steve spent 5/8 of his allowance on 15 meat pies and 10 quiches. After spending another $14.50, he bought the same number of meat pies and quiches. A quiche costs 50 cents more than a meat pie. a) Find the cost of a meat pie.
b) How much allowance does Steve have at first?
[S3 Maths / Principle of Accounts: Taxes] The title is fairly self-explanatory, presenter Matt Parker walks through the mathematics behind calculating the income tax. It's interesting that a lot of the formulae we use, and tend to use, are actually transformed versions of intuitive mathematics to make things much easier for ourselves. It's important to know the transformation process, though, and not blindly accept "Ah, this is the formula mentioned in the book, it must be co