By: Pawitra and Kevin, G.7

Energy transformations

Are vital to survival.

People have needed enough stored chemical energy in their bodies to change to kinetic energy.

The insides of the buildings were lit by candles, oil lamps and gas lights.

Coal and wood were used as fuel on fires.

People and goods were transported by carriages and carts pulled by horses and donkeys.

The insides of the buildings are lit by electricity.Cars, vans, trucks and buses are used to transport people and goods.These vehicles are powered by petrol or diesel engines.Airplanes are powered by a fuel called kerosene.

WORK

Occurs when a force moves an object through a

distance.

Is measured in newton-metres. This unit of work is

called the joule.

Measuring work

work = force x distance

Is used to show how energy transformed.

The 3 parts are :

a) Energy input

b) Energy converter or transducer

c) Energy output

This is the energy transfer diagram for bulbs:

It features arrows of different widths.

The width of the arrow indicates the amount of

energy it represents.

This is Sankey diagram for bulbs.

PLANTS AND ENERGY

Photosynthesis is called the process of making

food (in plants) using light energy.

Energy transfer diagram for photosynthesis:chemical (water) and light (sunlight) -> plants -> chemical

(glucose)

Energy and ourselves

The units used to measure energy in food are the

joule and kilojoule.

Chemical energy in food is released in a process

called respiration.

Oxygen is needed for our body to breathe and

released as carbon dioxide.

Water is used in our body or released in sweat and

urine.

Most energy that is released in our body is used for

movement and to keep our body warm.