Recent content by Gregoriorosso

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    A positive charge Q is located at the origin....

    the radius of the sphere is √2 L the surface of the sphere is 8*π*L^2
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    Question: pressure inside an object submerged in water

    as an engineer I observe that before diving the volume of air in your tube is proportional to 1.2 and after it is proportional to 0.8 =1.2 - 0.4 then from the equation P*V = constant at constant temperature you get: Pmsl*1.2 = P*0.8 the the pressure of water at the free surface inside the tube...
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    Question: pressure inside an object submerged in water

    as a theoretical physicist At the beginning I must state that we are modeling a system that is isothermal at the same temperature in the initial and final state + that the density of air inside the tube is uniform in both states + that the gravitational field is uniform and constant + that there...
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    B What are the biggest misconceptions about black holes?

    They told me that the density of water is approximately 1 kg/liter. That was long time ago, when I didn’t know the density of the atomic nuclei of oxygen or hydrogen. Some years later I was informed that the density of water is much lower than the density of atomic nuclei, but the density of...
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    B What are the biggest misconceptions about black holes?

    I am surprised by many statements about bh - let’s take density. In my normal life, it is defined as ρ = mass/volume but what’s the volume of a bh ? I guess 4/3 π R^3 ? as R = is 2GM/c^2 it seems to me that ρ = 3c^6/32πGM^2 A bh with 10^9 solar masses (that is a large one, but not the largest)...
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    B Effect of Density and Geometry on Gravity and Luminosity

    In your reference G is = 1 (it depends on the choice of units) in my notation 2*π*ρ*R = M and z = H for r = 0 the Fz is the total force, as Fr is zero and for r = 0 the expression of Fz in pag.1 of your reference becomes, in my notation, Fz = G*M*H/(R^2+H^2)^3/2 you can see that H/(R^2+H^2)^1/2...
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    B Effect of Density and Geometry on Gravity and Luminosity

    in every geometry always the pull is directed toward the center of mass - The force at the same distance from the center of mass is different for different shapes. In this particular system also without calculus the force is easily found = [G*M/(R^2+H^2)]*sin( a ) ; a is the angle earth- a...
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    A scenario in which a planet's gravity pulls away from center of mass

    sorry, I forgot: if the inertia of the planet is shielded but electromagnetic forces are still acting, the motion of the planet will be altered by the interaction with magnetic fields of the sun. Slowing down the rotation, longer and longer days. Don't know how fast. Also the sun light pressure...
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    A scenario in which a planet's gravity pulls away from center of mass

    I understood that you were looking for a planetary landscape with reverse gravitation everywhere on the surface, saving the planet integrity and the atmosphere, and you supposed that were effect of a surprising change of our actual terrestrial situation. That's why I didn't propose an...
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    A scenario in which a planet's gravity pulls away from center of mass

    forget the mass in the sky: problems with atmosphere, which will disperse-unless the sphere outside can stop it. Unfortunatly the gravitational effect of a cave sphere on the objects inside the cavity were zero, although the gravitational effect of the Earth were not changed. but for creative...
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