Calculating Work on Incline: Solving for Gravitational Force Work

AI Thread Summary
The discussion revolves around calculating the work done by gravitational force on a box being pushed up a frictionless incline. The user initially uses the formula Wg = mgh and calculates the height using the sine of the incline angle, resulting in a work value of 358.1 J. However, they realize that the work done by gravity should be considered negative since it opposes the direction of movement. The clarification leads to the understanding that gravitational work is stored as potential energy, confirming that the correct approach involves recognizing the sign of the work done by gravity. The final takeaway emphasizes the importance of considering the direction of forces when calculating work in physics problems.
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Homework Statement


A horizontal force of magnitude F = 197 N is used to push a box of mass m = 5 kg from rest a distance d = 13 m up a frictionless incline with a slope q = 34°.


Homework Equations


How much work is done on the box by the gravitational force during this same displacement?


The Attempt at a Solution


Wg=mgh
Wg=5*9.81*7.3
i got 7.3 by using sin34=h/13
Wg=358.1 J
The answer i got is wrong according to the online hw. What am i missing? did i use the wrong formula?
 
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Maybe it would be negative?

Work by you is +, work by gravity is stored as potential = (-)?
 
wow, it is negative. thank you very much!
 

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