Raahulan’s School Blog

Analyse why red sunsets can sometimes be more impressive when there is more dust or pollution in the air than usual.

The pollutant aerosols in the atmosphere tend to settle with time into layers, with larger particles forming the denser layers closest to the ground. Sunlight fades gradually and takes on an orange-red hue as it traverses these layers. The scattered light loses more of the shorter-wavelength colours, so that mainly red gets through. The sky takes on a dull red glow; the shades of red become darker nearer the Earth’s surface as the scattered light comes from the increasingly dense layers of the lower atmosphere.

Describe what happens inside water droplets to cause a rainbow and explain how you can tell whether a rainbow is a primary or secondary.

White light goes into the raindrops and because different colour light has different velocities so as the refractive rays come out a raindow is formed. A primary rainbow has red at the top and blue at the bottom and a secondary randow has blue at the top and red at the bottom.

Investigate the two types of sight defect- long-sightedness and short sightedness.

Find the following information:

What causes the defect?

The defect can come because of heredity, looking close to what you are trying to read or see or straining your eye to look from far distance. It can be also caused by injuries on the eye.

The symptoms displayed

It would be hard to see far distance of to see short distance

Propose what sort of lens may be used to correct each vision.

To treat long sightedness you will need to wear glasses with convex lens and with short sightedness you will need to wear glasses with concave lens.

Fibre optic technology offers many advantages when used in medical applications.

a. describe how optical fibre may be used in medical applications

You can do key hole surgery to see the body inside and is mainly done in surgery to see where doctors are operating. They are used in endoscopes.

b. identify the traditional medical techniques that optical fibres might replace

Optical fibres are increasingly being used instead of copper wire to transmit data and communications because they are thinner, cheaper, more durable and can carry more information.

c. Evaluate the benefits of fibre optic technology to medicine

The benefits of fibre optic technology to medicine is that images are transferred very fast, have a magnifying strength of 2000x and are cheaper to use and have.