energy
conservation of energy
https://docs.google.com/document/d/1WfcGb99vTI2WBUdtDbn1rvvmWDms6riF3sCdnX2W1GA/edit?usp=sharing
https://www.loom.com/share/23df44fae62a4659a5f1a17610b99af4
lesson on efficiency and power.
https://docs.google.com/document/d/1VYFB9Q143o9KQZeDedoVKbWMhreXo2onLIh5fmRhsDg/edit?usp=sharing