3.6 Problem Solving
Conservation of Energy
Conservation of Energy
The Law of Conservation of Energy states energy cannot be created or destroyed. This law is elegant and can be used to solve an unknown in a problem.
Ebefore = Eafter
Because we're focusing on mechanical energy, let's include Ep and Ek. We'll also include Eh, as we'll sometimes need to determine lost energy.
Ebefore = Eafter
Epo + Eko = Epf + Ekf + Eh
Epo + Eko = Epf + Ekf + Eh
Where:
Epo = initial potential energy = mgho
Eko = initial kinetic energy = 1/2 mvo2
Epf = final potential energy = mghf
Ekf = final kinetic energy = 1/2 mvf2
Eh = energy lost to heat.
Eko = initial kinetic energy = 1/2 mvo2
Epf = final potential energy = mghf
Ekf = final kinetic energy = 1/2 mvf2
Eh = energy lost to heat.