renamed:    classicalmechanics/twoMassSpringCouplingFig1.odg -> phy487/twoMassSpringCouplingFig1.odg
renamed:    classicalmechanics/twoMassSpringCouplingFig1.png -> phy487/twoMassSpringCouplingFig1.png
new file:   phy487/twoMassSpringCouplingFig2.png
new file:   phy487/twoMassSpringCouplingFig3.png
new file:   phy487/twoMassSpringCouplingFig4.png