The Wave Equation

http://twyfordigcsephysics.blogspot.co.uk/2013/10/the-wave-equation.html

http://twyfordigcsephysics.blogspot.co.uk/2013/10/a-water-wave-has-frequency-of-2-hz-and.html

Waves

http://twyfordigcsephysics.blogspot.co.uk/2013/10/waves.html

Inclined Plane and efficiency

http://twyfordigcsephysics.blogspot.co.uk/2013/09/efficiency-of-inclined-plane.html

Power

http://twyfordigcsephysics.blogspot.co.uk/2013/09/power.html