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    Buoyant Force

    Got it! THANK you! You have been so helpful
  2. T

    Buoyant Force

    I know Volume would equal .09x.09xh, but wouldn't this height be referring to be side of the 1.3m? aren't we looking for the part of the .09 that is submerged? the post seems to be laying horizontally in the water, not straight up. Also, when I reduce and isolate the height, I obtain .531m or...
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    Buoyant Force

    So setting it equal... 1029 x Vdw x 9.8=420 x (.09 x .09 x 1.3) x 9.8 Vdw=.0043 m3 How do we find the height from this? Do we subtract it from the volume of the post?
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    Buoyant Force

    Fb=densityw x Volumedw x g =1029 x Vdw x 9.8 would we set this equal to the density of the post x Volume of post x g?
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    Buoyant Force

    Ok, it can either be densitywaterx Volumepost x g=masspostxg or densitywaterx Volumepost x g=densitypost x Volumewater x g does this look right?
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    Buoyant Force

    I believe the buoyant force is equal to the gravitational force, as the object is at rest.
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    Buoyant Force

    Greater than the gravitational force or m x g. But on the table. the force acting on the post is equal to that of the post acting on the table. In other words, the gravitational force is equal to the normal force. Am I wrong to say that the buoyant force must be greater than the gravitational...
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    Buoyant Force

    If the post is floating, wouldn't the buoyant force have to be greater? Would we use the density of the wood on the water to find it instead of the density of the water?
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    Buoyant Force

    ha! oh yes-I did mean water. Sorry. Ok, no the wood is not entirely submerged. But the problem does not given us the percent it is submerged-how do we find that?
  10. T

    Buoyant Force

    Ok, Archimedes's principle states that the magnitude of the buoyant force=weight of the fluid displaced by object Fb=density of fluid x volume of object submerged x g =1029 x (.09 x .09 x 1.3) x 9.8 =106.187 N I don't see where to go next.
  11. T

    Buoyant Force

    Homework Statement A 9 cm square wooden post (density=420kg/m3) is 1.3m long and floats in sweater (density=1029 kg/m3. How deep is the post submerged in the water? The picture shows a 9cm x 9cm cross section of the post. Homework Equations Fb=density of liquid x volume of liquid submerged x...
  12. T

    Absolute Pressure

    The tuna's density must be the same as the surrounding water. Would we do this: absolute pressure of water=density of water x gravity x depth and solve for density of water? we could then equate density=m/v and we have the mass of the fish. 2.44atm=density x 9.8 x 15m density=.01698...
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    Absolute Pressure

    Since we are given the pressure at the depth, is it redundant to include it in the equation? ok, I see what you mean about water not changing density with depth. But how do we solve for the fish volume without dealing with the tuna's density?
  14. T

    Absolute Pressure

    I guess I do not understand the equation well. In P=pgh, density would be referring to that of the object, Pressure would be referring to that of the incompressible fluid, and h the height of the column of fluid above location. This is what I have in my notes. If we multiply the tuna's density...
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    Absolute Pressure

    Ok, I think that would mean the body would have the same density as the fluid. But why does the above mean the tuna is reaching all the way to the surface? Are we calling where the tuna is as h=0?
  16. T

    Absolute Pressure

    Homework Statement A 410kg bluefin tuna rests motionless at a depth of 15m below the ocean's surface. The absolute pressure at this depth is 251,700 Pa. What is the volume of the fish? Homework Equations absolute P=gauge Pressure+atmospheric pressure 1atm=1.03e5Pa P=density x g x height...
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    Conservation of energy

    Yes, I do see it now-my picture did not have the radius being pointed horizontally and vertically, just down the middle. Thank you for all your help!
  18. T

    Conservation of energy

    yes, it is just like that, except flipped so that the curve is on the right and height on the left.
  19. T

    Conservation of energy

    Ok, now I see how to do this. I obtained 17.2 m/s, which is correct. Thank you! However, I still don't see how the radius could be equal to the height of the ramp. There is a picture provided that looks like a skateboard ramp, with a strict vertical height and then the inside being curved with...
  20. T

    Conservation of energy

    Would the radius be the initial height? When it is rolling? I'm not exactly sure.
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    Conservation of energy

    Homework Statement A block of mass 10kg starts at the top of a frictionless track which forms a quarter circle with radius 10m. It is given an initial downward velocity of 10m/s. What is the velocity at the bottom of the track? Homework Equations KEtranslational, f+ KErotational...
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    Torque on a wrench

    Thank you! That was most helpful.
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    Torque on a wrench

    hmm...my calculator was in radian mode. I need degree mode, don't I? ha
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    Torque on a wrench

    Homework Statement (a) Suppose you have just barely loosened a rusty bolt. Your mass is 80 kg and you have a wrench of length L = 50 cm placed as shown in the diagram below, and hung off the end so all your weight was applied, in the downward direction, to the end of the wrench. What is the...
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    Buoyant Force on a man

    I don't have access to the answer yet-it's a web assign HW question.
  26. T

    Buoyant Force on a man

    yes, I tried 1.225 and 1.2. Both are incorrect.
  27. T

    Buoyant Force on a man

    Yes, I tried that as well and obtain 833N, which is also incorrect. I did this first, and then thought we need to use the density of the air.
  28. T

    Buoyant Force on a man

    Homework Statement A certain man has a mass of 85.0 kg and a density of 995 kg/m3 (exclusive of the air in his lungs). (a) Calculate his volume. .0854 m3 (b) Find the buoyant force air exerts on him. N (c) What is the ratio of the buoyant force to his weight? (buoyant force / weight)...
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    Fluid Statics/depth in a cylinder

    No, never heard of that. What is Gaussian elimination?
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