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1. I want to simulate the effect of a free falling body and how its speed changes swiftly as it hits the water surface. This is to show the power of water buoyancy and its effect on gravity (as anti-gravity force.)
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Do you need to consider the drag force or just consider the bulyant force?

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2. I want to simulate the effect of high water pressure of deep sea. I want to submerge a container (after entering its properties) and see when this container gets imploded by sheer water pressure.
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How depth/ how high is the pressure range? Need data of water density as function of depth.

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3. I want to simulate the effect of water buoyancy on free fall. I'm especially interested in showing how fluid properties (density, salinity, temperature) and gravitational constant (g) affect free fall's terminal velocity. I need this to simulate probes sent to outer space esp. Venus (atmosphere 90 times thicker than earth), Mars (gravity constant half of earth) and Jupiter (gravity 13 times but size 100 times and atmosphere - I think - nearly as thick as water.)
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Need density of water as function of salinity and pressure.
It is better if you can provide a physics model with proper parameter values.

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a. Ability to record the simulation data whether as a graph or output file.
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It can be done with EJS. However, I need to know what kind of data need to be drawn/saved.

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b. Ability to load an image or vector graphic in place of the solid brick. This is to make simulation feel closer to real world.
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Please provide image file (gif/jpeg or png)

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c. Ability to change gravitational constant (g).
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It is basics feature. Let me know the range you want to be adjusted.
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d. Ability to change salinity of water.
e. Ability to change water temperature.
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Need model related to salinity of water and temperature(e.g. density as function of salinity or temperature.)

I can created the simulation if I have full physics model (with proper parameters).
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f. Ability to specify properties of atmosphere.
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What dose this mean? What need to be changed?
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g. Larger screen size.
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What is the screen size you need!