posted by John on .
If a box is being pulled up a hill at an angle to find work, its W=Fdcos(angle)
If a hiker is walking up a hill, the work done is W=mgh right?
When do you know when you can use what formula?
No, that is not exactly the formula.
What is better is force*distance*cosTheta, where Theta is the angle between force and distance.
In the case of the hiker, mg is downward, but the force is in the opposite direction, h is vertical, so the angle between force and distance is zero, so it ends up mgh (coszero)=mgh