P6 Sources and Forms of Energy (Concept Map)
Primary 6 Science — Concept Map
Created by Miss Clarissa Ng · www.clartutors.com
Energy
the ability to do work — measured in Joules (J), cannot be created or destroyed
two categories
Potential energystored energy
Kinetic energyenergy of motion
Other common formsheat, sound, light and electrical energy
kinetic energy
Moving objectsthe energy a moving object has because of its motion
Speed and massthe greater the speed, or the greater its mass (at the same speed), the more kinetic energy it has
At resta stationary object has no kinetic energy at all; the same ball moving faster has more kinetic energy
gravitational potential energy
Held above the groundstored energy an object has because of its position above the ground
Height and massthe greater its height, or the greater its mass (at the same height), the more potential energy it has
Fallingas it falls, the potential energy is converted to kinetic energy; at ground level there is no potential energy
elastic potential energy
Stretched or compressedstored energy in objects such as rubber bands and springs
What it depends onhow far the object is stretched or compressed
Thicker or more springsa thicker elastic object, or more springs used, stores more potential energy
chemical potential energy
Food stores itthe energy in food is chemical potential energy, and it came from the Sun
Food, fuels and batteriesstored energy released by chemical reactions — food for life processes, fuels for heat, batteries for electricity
energy is converted in
Ball collisionthe kinetic energy of one ball is transferred to another when they collide
Bouncing ballloses energy on each bounce because some kinetic energy is converted to heat and sound
Power stationshydroelectric: GPE → KE → electrical · fossil fuel: chemical → heat → KE → electrical
sources and saving energy
Sun · Water · Windrenewable
Fossil fuelsnon-renewable and polluting
Trade-offssolar panels do not work at night and is costly · dams harm aquatic wildlife · windmills need high wind speed
At homeswitch off lights when not in use · use fans instead of air-conditioners
Laundrywash only when there is a full load
two rules that always hold
Never used upenergy is converted from one form to another — it is never created or destroyed
Measured in joulesthe joule (J) is the unit of energy, and its symbol is J