Answer:
6m ramp
Explanation:
I'm assuming you need the ramp which will make it the easiest which would be the 6m ramp because since it is longer it will be a more gradual incline making it easier to move the boxes.
True mechanical energy is the sum of potential and kinetic energies
See photo attached
Hope this sort of helps ʕ•ᴥ•ʔ
You learn new thing every day!!!
Explanation: