Friday 28 February 2020

The Best GCSE Calculator


The features on this make many of the problems much easier to solve.
For calculator papers this the polynomial solving feature alone ( quadratic formula) makes this calculator worth it, but also with the tables, the ratio solver and the simultaneous equation solver makes this calculator a must for GCSE Maths. I know I bought two of them and recommend them to my students.
Casio FX-991EX CLASSWIZ

Ball Bearing in Free fall

A ball bearing being dropped and thrown. taken with a strobe flash. Although the ball bearing on the right is moving towards the right it is falling at the same rate as the ball that is dropped. It doesn't seem obvious but that's science.

Saturday 22 February 2020

Malus Law


Shining a light through two polarising lenses. The first cuts out all the light except in one plane. Rotating the other into a plane at 90 degrees, can wipe out the other. Try looking at a led TV screen (polarised light) with polarising lenses and see what happens as you rotate them.

Saturday 15 February 2020

A Really Sharp Pencil

The most useful item in a student's toolkit is the sharp pencil, long enough to hold and make sure its really sharp. Always have one pencil or better still two. Used lots in Science and Maths too. For graph work a sharp pencil can get an extra mark for those points being accurate, and a sharp pencil improves the line. A good rubber (not one on the end of a pencil) makes the mistakes easier to change.

Sunday 9 February 2020

A tall order "hiding a light under a bushel" and do a fun chemistry experiment about that. But we managed to put the fire under the bushel out with a homemade fire extinguisher

Alcohols to Acids

Butanoic Acid is made from heating butan-1-ol with Acidified Potassium dichromate and refluxing for 30 minutes of so. The potassium Dichromate changes from orange to green as it is reduced and the alcohol is oxidised. After the reaction is complete then the apparatus is changed and set up as in the photograph to allow the butanoic acid to be distilled off from the mixture leaving the chromate behind and the butanoic acid is collected in the conical flask.

Order of Reactivity

Order of reactivity of metals - this was a tough one for the students because they had to devise their own experiments; with a lot of help, ...