Hello, it is I. Welcom to another class of physics. This time we used battery to power up the energy display, then use the Joules to pull a heavy block off the ground. There are few formulas that need to remeber. F=ma=mg, W=FD(D=distance), Effiency=W/energy used*100%. These will help the kids to do their hoemwork but I also told them in class. It was fairly an easy project to build but needed some critical thinking to finished the expriments. Hope they have learned somthing and had fun with it.