There's a good chance you could improve your teaching if you were to:
efficiency as a technical term, perhaps reserving
effectiveness for the more general idea of getting stuff done well
using apparatus, words and diagrams together to develop accounts
developing physical descriptions before accounts that use energy and power
emphasising the practical consequences of calculations with power and energy
Work through the Physics Narrative to find these lines of thinking worked out and then look in the Teaching Approaches for some examples of activities.
calculating without sharing the purpose of the calculations
running together different steps of multi-step arguments
confusing snapshots with processes
These difficulties are distilled from: the research findings; the practice of well-connected teachers with expertise; issues intrinsic to representing the physics well.
Prepare for teaching across the topic using these links
topic kitset topic path core ideas (topic) decisions to make (topic) suggestions (for the topic) topic issues
This is a nugget in the TL thread – connect all three threads from any link
Physics Narrative (PN) Teaching & Learning Issues(TL) Teaching Approaches(TA)