by Stuart Kelly | 2 Jul 2014 | Maths
Given: a = b Multiply by a: a2 = ab Subtract b2: a2 – b2 = ab – b2 Factorise: (a + b)(a – b) = b(a – b) Divide by (a – b): (a + b) = b Substitute for b: a + a = a Simplify: 2a = a Divide by a: 2 = 1 Clearly, this is impossible. So...
by Stuart Kelly | 13 Apr 2014 | General
This is a classic. Energy = Power x Time So given a question like “How much energy is converted if a 100W light bulb is on for 1 hour?” it’s obvious that you multiply 100W by 1 hour and get the answer 100 Joules. WRONG!! The formula only works if ALL...
by Stuart Kelly | 9 Apr 2014 | General
… thought of my students. An hour with me and I promise your brain won’t turn to mush if you come across a question like this. Share...
by Stuart Kelly | 12 Nov 2013 | Physics
“Poets say science takes away from the beauty of the stars – mere globs of gas atoms. I too can see the stars on a desert night, and feel them. But do I see less or more? The vastness of the heavens stretches my imagination – stuck on this carousel my...
by Stuart Kelly | 9 Nov 2013 | Maths
I just added a sheet of circle theorems. Unfortunately, you just have to learn these, but it’s well worth it. You need to able to spot which theorem to use when you see a question. The best way to get better at this is practice. The more examples you do, the...