Cartesian to curvilinear coordinate transformations

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Transforming between Cartesian and curvilinear coordinates can be complex, especially in vector fields like E&M. Using vector notation enhances clarity and independence from specific coordinate systems, making calculations more intuitive. Instead of focusing solely on Cartesian components, it's beneficial to express vectors in terms of dot products or magnitudes. This approach allows for a more conceptual understanding before resolving into specific coordinates for integration. Emphasizing vector notation can simplify the transformation process and improve problem-solving efficiency.
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Homework Statement


Is there a more intuitive way of thinking or calculating the transformation between coordinates of a field or any given vector?

The E&M book I'm using right now likes to use the vector field

## \vec F\ = \frac {\vec x} {r^3} ##

where r is the magnitude of ## \vec x ##In Cartesian coordinates, this looks like

## \frac {x \hat x + y \hat y + z \hat z} {\sqrt {x^2 + y^2 +z^2}^3} ##

In problems such as finding the flux through a sphere, it's difficult to use cartesian coordinates as it's very algrebra intensive, but I find it hard to convert between different coordinate systems. It also seems really unnecessary to simply look up the values of x,y,z and their respective ## \hat x ## directions for the components. Is there a better way to go about thinking and converting fields?
 
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One of the advantages of using vector notation is that it should be independent of your coordinate system so to answer your question about "a more intuitive way..." I would say; Yes, use the vector notation as much as possible. Where you can, rewrite component formulas in terms of dot products or vector magnitudes. For example if you need the ##x##-component of a vector ##\vec{v}## write that as ##v_x=\hat{\imath} \bullet \vec{v}##. Granted you'll eventually need to resolve coordinates for such things as integrating over a surface but if you do most of your conceptual work in the general notation first, you often can select the coordinate system that makes this easiest.
 
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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