What Force is Necessary to Submerge Mary in Fresh Water?

AI Thread Summary
To determine the force necessary to submerge Mary in fresh water, her specific gravity of 0.95 and weight of 660 N are used. The mass of Mary is calculated to be approximately 67.3 kg, leading to a buoyant force of about 63.94 Newtons. The discussion highlights the importance of understanding the buoyant force formula, which includes density (ρ), acceleration due to gravity (g), and volume (V). Participants express confusion about fluid dynamics, emphasizing the complexity of the topic. Overall, the conversation revolves around applying physics principles to solve the problem of submerging an object in water.
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What force is necessary to just barely submerge (push Mary under fresh water) Mary if her average specific gravity is 0.95 after taking a deep breath and her weight in air is 660 N?


F=mg ; Force of buoyancy=ρgV;



F=mg
660/9.8=mass of air
mass of air=67.3
force of buoyancy= 67.3 x 0.95
=63.94 Newtons

is this right?! i am panicking! physics is so hard omg. fluids are so difficult to understand! waaaaaaaaa
 
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Do not panic! You have the formula for the buoyant force

Force of buoyancy=ρgV.

What do ρ, g, V mean?

ehild
 

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