This is the go to physics resource I use. The MOP part is unparalleled in helping students get to the core concepts in physics- I highly recommend it.
It is what I built my physics curriculum around because it is so thorough.
How I Use It
I use MOP as homework and classwork- students find the material challenging, and have to sometimes really go back and review to get the questions correct. When I stopped using for a unit, they asked to go back becsue of how well theylearned from it.