What's the Matter With Bubbles? (one day)
A Rocky Problem (one day)
Putting Bubbles to the Test (three days)
Nailing Down Some Particles (two days)
http://www.glenbrook.k12.il.us/gbssci/phys/Class/newtlaws/u2l4a.html
http://www.phy6.org/stargaze/Snewton3.htm
http://archive.ncsa.uiuc.edu/Cyberia/VideoTestbed/Projects/NewPhysics/newtons_3.html
http://www.mansfieldct.org/schools/mms/staff/hand/lawsN3L.htm
http://www.batesville.k12.in.us/physics/PhyNet/Mechanics/Newton3/Third_Law_Quiz.html
http://www.usoe.org/curr/science/sciber00/8th/forces/sciber/forces.htm