A3:Work, energy and power

the principle of the conservation of energy
• that work done by a force is equivalent to a transfer of energy
• that energy transfers can be represented on a Sankey diagram
• that work W done on a body by a constant force depends on the component of the force along the
line of displacement as given by W = Fs cos θ
• that work done by the resultant force on a system is equal to the change in the energy of the system
• that mechanical energy is the sum of kinetic energy, gravitational potential energy and elastic
potential energy
• that in the absence of frictional, resistive forces, the total mechanical energy of a system is conserved
• that if mechanical energy is conserved, work is the amount of energy transformed between different
forms of mechanical energy in a system