Section 4: Energy Resources and Energy Transfer

4.12 know and use the relationship Kinetic energy = ½ x mass x velocity2 K.E = ½ x m x v2

4.13 understand how conservation of energy produces a link between gravitational potential energy, kinetic energy and work An object of mass, m weights mxg newtons. So the force, F, needed to lift is mg. If we raise the object through a distance h, the work done on...

4.14 describe power as the rate of transfer of energy or the rate of doing work Power is the rate of transferring energy or doing work. Its measures how fast energy is transferred.

4.15 use the relationship between power, work done (energy transferred) and time taken power=(work done)/time P=W/t

4.16 describe the energy transfers involved in generating electricity using Wind: Winds are powered by the Sun's heat energy. Wind is a renewable source of energy. Wind mills have been used o grind corn and power machinery like pumps drain lowland areas. Today, wind...

4.17 describe the advantages and disadvantages of methods of large- scale electricity production from various renewable and non- renewable resources Renewable Resources: Wind energy: Advantages: Relatively cheap to set up clean – no waste products Relatively efficient...

4.5 describe a variety of everyday and scientific devices and situations, explaining the fate of the input energy in terms of the above relationship, including their representation by Sankey diagrams Whenever we are transferring energy, proportion of input energy is...

4.6 describe how energy transfer may take place by conduction, convection and radiation There are three basic ways energy can transfer from place to place: conduction, convection and radiation. Conduction: Conduction is the transfer of energy through substance mainly...

4.7 explain the role of convection in everyday phenomena Boiling water uses the role of convection to transfer heat. When fire is started, molecules at the bottom gets heated and expands. It gains kinetic energy and rises upwards and the molecules at the top sinks...

4.2 describe energy transfers involving the following forms of energy: thermal (heat), light, electrical, sound, kinetic, chemical, nuclear and potential (elastic and gravitational) For energy to be useful, we need to be able to transfer it from place to place and be...

4.8 explain how insulation is used to reduce energy transfers from buildings and the human body. Energy-efficient houses reduce energy transfer by using two layered walls and double glazing windows. The wall is made wide layers of different materials. The outer layer...

4.9 know and use the relationship between work, force and distance moved in the direction of the force work=force x distance W=F x d

4.10 understand that work done is equal to energy transferred Doing work means the energy is either decreased or increased. If a weight of 500N is raised 2m, 1000J of work is done. That means energy is increased by 1000J. Therefore work done is equal to energy...

4.11 know and use the relationship gravitional potential energy=mass x gravitional acceleration x height G.P.E=mgh

4.1 use the following units: kilogram (kg), joule (J), metre (m), metre/second (m/s), metre/second2 (m/s2), newton (N), second (s), watt (W). Unit of mass: kilogram(kg) Unit of energy: joule(J) Unit of distance: metre(m) Unit of speed or velocity: metre/second (m/s)...

4.3 understand that energy is conserved Energy is not created or destroyed in any process. It is just converted from one from type to another.

4.4 know and use the relationship Efficiency = Useful Output Energy/ Total Input Energy