coba di link-link ini teman-teman untuk referensi tambahan tentang usaha dan energi....!!!!!!selamat mencoba...!!!!!
Written on 19.13 by sianturikomkom
http://theory.uwinnipeg.ca/physics/work/index.html
http://www.efm.leeds.ac.uk/CIVE/CIVE1140/section03/mechanics_sec03_full_notes02.html
http://hyperphysics.phy-astr.gsu.edu/hbase/work.html
http://www.edinformatics.com/math_science/work_energy_power.html
http://www.sciencejoywagon.com/physicszone/05work-energy/
