Is a 15kg object capable of generating 147N upward force in water?

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The discussion centers on calculating buoyancy, where the upward force is determined by the equation buoyancy force minus the object's weight. The correct formula involves the mass density of water and the volume of the submerged part of the object. A target upward force of 147N for a 15kg object is questioned, as it may be too high for smaller objects like ice cubes but appropriate for larger vessels like ocean liners. The importance of considering the specific volume and density of water is emphasized in designing buoyant systems. Overall, the calculations provided are deemed accurate for assessing buoyancy in various contexts.
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I believe that the way to calculate buoyancy is buoyancy force-weight of object= upward force, which is PVg-mg= upward force. If I'm wrong please tell me. I set a target of 147N(15kg) upward force for my project product. Is it that strong? Give me your thoughts.
 
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Maths looks right.

15kG is about the weight of two Bowling balls.
 
If your "P" is the mass density of water and V is the volume of water of that part of the object below water, then, yes, the bouyancy force is PVg. The total force would be that minus the weight, mg. When the object is "floating", the two must cancel so that the total force is 0, neither up nor down.

As for a target bouyancy of 147 N, what is your question about it? For an icecube that would be much to high. For an ocean liner, it would be much too low!
 
I've designed many many buoyant systems for seawater. If figure volume in cubic feet and multiply by 60 lbf per cubic foot. The water is a little heavier than that, but I like the margins in case my material absorbs a little water.
 
I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...

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