How much work would it take to push a # 9 kg # weight up a # 12 m # plane that is at an incline of # pi / 6 #?
There is a vertical down force, called weight, which is given by
However, you can't actually move vertically down, because the plane gets in the way, so gravity instead acts as close as it can to straight down - it acts down the plane.
Using trigonometry, you can find the angle down the plane is
If this is the force down the plane, the force up the plane in order to move it must be the same, so
The question is actually asking for work, which is given by