WORK,ENERGY & POWER (THEORY)( IGCSE 0625 CLASSIFIED WORKSHEET WITH ANSWERS)

Worksheet includes 28 Theory questions from past 10 years. Also covers
Identify changes in kinetic, gravitational potential, chemical, elastic (strain), nuclear and internal energy that have occurred as a result of
an event or process
• Recognise that energy is transferred during events and processes, including examples of transfer by forces (mechanical working), by electrical currents (electrical working), by heating and by waves
• Apply the principle of conservation of energy to simple examples
Recall and use the expressions kinetic energy = ½mv ^2 and change ingravitational potential energy = mg∆h
• Apply the principle of conservation of energy to examples involving multiple stages
• Explain that in any event or process the energy tends to become more spread out among the objects and surroundings (dissipated)
Describe how electricity or other useful forms of
energy may be obtained from:
– chemical energy stored in fuel
– water, including the energy stored in waves,
in tides, and in water behind hydroelectric
dams
– geothermal resources
– nuclear fission
– heat and light from the Sun (solar cells and
panels)
– wind
• Give advantages and disadvantages of each method in terms of renewability, cost, reliability, scale and environmental impact
• Show a qualitative understanding of efficiency
Understand that the Sun is the source of energy for all our energy resources except geothermal,nuclear and tidal
• Show an understanding that energy is released by nuclear fusion in the Sun
Recall and use the equations:
efficiency =( useful energy output/energy input) × 100%
efficiency =( useful power output/power input )× 100%
Demonstrate understanding that work done = energy transferred
• Relate (without calculation) work done to the magnitude of a force and the distance moved in the direction of the force.
Relate (without calculation) power to work done and time taken, using appropriate examples
Recall and use W = Fd = ∆E
Recall and use the equation P = ∆E/t in simple systems