Is Work Done Pushing a Car Up an Incline Independent of the Angle?

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The discussion centers on whether the work done in pushing a car up an incline is independent of the angle of the hill, focusing on the change in height (h). It highlights two homework problems: one involving a backpack where the angle is not needed, and another with a car where the angle is essential for the correct solution. The key equations mentioned are W=F(d cos θ) and W=Fh, noting that height (h) is dependent on the angle (θ). The participant expresses confusion over the necessity of the angle in one problem but not the other, despite both being solvable. Ultimately, understanding when to incorporate the angle is crucial for accurately calculating work done in these scenarios.
drewdiddy
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Homework Statement


Work pushing car up incline.

More of a generalization than anything. Is the work done independent of the angle of the hill seeing as all we're concerned with is the change in h?

I had two problems on the homework. One carrying a backpack up a hill where the angle wasn't given and not necessary and another with pushing a car up a hill where the angle was given and necessary to get the correct solution. Trying to differentiate when I need the angle and not

Homework Equations



W=F(d cos <) and W=Fh (when h=cos< x d)

The Attempt at a Solution

 
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Realize that h is dependent on theta . To get the work done out of a problem, one method is through the final height reached. You can also find it through force times the inclined distance moved.
 
doh. I knew that. It's late here :) What I meant was that I was given two work problems. Both give mass of object, both give h, one gives angle and the other does not. But from what I see the work is calculable on both of them. However, the angle is necessary to use in the problem where it is given. I'm unable to wrap my head around why that is.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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