- #1
Jozefina Gramatikova
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Vector calculus- region-density-mass
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- #2
Chandra Prayaga
Science Advisor
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The attempt that you posted is too small and I cannot click on it to get a better view. But from what I can see, I suggest the following.
1. Understand, from the ranges of x, y and z given by you, the shape of the region you are interested in. In other words, answer the first question and sketch the region. In your graph, you only showed a few isolated points. You did not sketch the region in space.
2. The relevant equation posted by you is not adequate. Density = mass / volume is good only if the density is constant. In your case, the density depends on position (your equation: ρ = 1 + z). Then you must use the differential form:
dm = ρ dV,
and integrate this to get the total mass. It will be a triple integral.
1. Understand, from the ranges of x, y and z given by you, the shape of the region you are interested in. In other words, answer the first question and sketch the region. In your graph, you only showed a few isolated points. You did not sketch the region in space.
2. The relevant equation posted by you is not adequate. Density = mass / volume is good only if the density is constant. In your case, the density depends on position (your equation: ρ = 1 + z). Then you must use the differential form:
dm = ρ dV,
and integrate this to get the total mass. It will be a triple integral.
- #3
Jozefina Gramatikova
- 64
- 9
Chandra Prayaga said:
I hope you can see the picture better now. I was wondering if I need the whole rectangle as a region or just the purple triangle that I sketched there?
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Your sketch is nowhere close to being right. It is a three dimensional solid.Jozefina Gramatikova said:
What is the range of z? For some arbitrary z in that range, what does the XY lamina look like?