Electric Circuits

Reflection of the Electric Circuit-building activity

I felt very fun building the electric circuit. I learnt how to make parallel and a series circuit. I also learnt that if one light bulb in a series circuit is blown the others will also turned off, while in a parallel circuit when a light bulb is blown the others wouldn’t.  It’s very fun building an electric circuit.

Light and Heat

Refraction of light

Light travels in a straight line but when it enters another medium it would be seen to bend.

How does a lens work?

A lens is a plastic or glass, which refracts light to form an image. When we look through a lens it will seemed like it was distorted. This because light undergoes refraction as it travels from air to glass and back to air again. Lenses are usually used to magnify objects. The examples are magnifying glass, microscopes, spectacles, cameras and telescopes.

Dispersion of light through a prism

White light is actually made up of different colours. We can prove this by shining white light to a prism, a a transparent plastic or glass object with smooth surfaces and can refract light. It occurs because, light travels at different speeds and the different colours refract at different angles as they pass through a prism.

Dispersion of light through water droplets

Water droplets can also act like a prism. The water droplets refract on sunlight.

Transfer of Heat

Conduction: Heat is transferred from one object to another. The example is, from the heat of boiling water to a spoon.

Convection: The transfer of heat from one region to another by the movements of fluids. The example is, from cold water to hot water.

Radiation: It is the release of heat from the surface

Annual project The annual project is very fun we made the pyramid,miniature ,ratio posters, booklet and also the PPT.

Seperating mixtures Seperating mixtures can be done by sieving,decanting,filtration,desalination and evaporation.

Physical and chemical change When physical change is is done,no new materials are formed while when physical change is done,new materials are formed.

Human population Factors affecting human population size -Birth rate    The birth rate isthe number of live babies born ina year for every 1000 people.   A high birth rate:    -Early marriges    -Lack of knowledge of birth control -Death rate The death rate is the number of people dying in a year for every 1000 people.   A high death rate:    -diseases     -famine    - natural disasters -Decrease in population size   A people considered ageing when:    -people under the age of 15 make less than 30% of the population.    - people above the age of 65 make up more than 6% of the population. People density Human migration is human movement from one area to another. Immigration Immigration takesplace when people move to another country permanently. Emmigration Emigration takes place when people move out of the country permanently.