When you have worked out the input of your pulley ( from the newton meter) for different loads, you need to calculate the efficiency. You must then plot a line graph with efficiency up the side and load on the bottom. You then need to describe the pattern and expalin it, and evaluate your experiment.

input = force on newton meter x 3m for a 3 pulley system

output = load (in N) x 1m vertical height

efficiency = output/input x 100%

In order to get a merit or distinction on the current assignment ( tomatosphere) you will need to complete the homework set today by next monday.

We made and tested hydrogen using sulphuric acid and zinc as our reactants. Metals react with acids to make a metal salt and hydrogen ( in this case zinc sulphate). The hydrogen is collected under water, and displaces the water in the test tube. The test for hydrogen is a squeaky pop with a lit splint. Hydrogen is explosive and reacts with oxygen in air to form water. hydrogen exploding

We used live maggots to prove that when organisms respire they release carbon dioxide. The tube with maggots in and bicarbonate indicator turned purple, wheras the other tube stayed orangy – red. Some students were scared of the maggots but fishermen warm them up in their mouths.

We put some chocolate in a microwave, after removing the turntable. We found that the chocolate melted in 4 places, 6 cm apart. The wavelength of the microwaves in the oven were 12 cm ( because the wave goes up and down). Ellie and Sam scoffed most of the chocolate!

article - be aware of American spelling of fibre.

You must know what total internal reflection is – how and where fibre optics are used – and what the critical angle is.