A .4 kg mass moves up 40 cm along an incline. The vertical height of the incline is 7.0 cm. The potential energy change is?? I used the formula for PEC. 1/2k(deltaX)^2 which got me to 320 joules. That is wrong though. What am i doing wrong??? If a force of .85N pulled parallel up along the surface of the incline is required to raise the mass back to the top of the incline, how much work is done? i used W=fd w=.85(40) w=34 but that answer is wrong. Im doing something wrong.