Buoyancy Definition and 413 Threads

Homework Statement A 100g object having a density less than that of water is placed into a beaker half full of water. The beaker is then placed on a triple beam balance. Would be measured weight be equal to, greater than, or less than the weights of the water, the beaker, and the object added...

Homework Statement A cube of side length 3 cm floats in water (density = 1g/cm^3) with 1 cm floating above the water. What is the density of this cube? Homework Equations Fbouyant = ρfluid*g*Vsubmerged Fg= mg The Attempt at a Solution I am having problems figuring out what the...

Homework Statement 4. The bottom half of a tank is filled with water (ρ = 1.0 x 103 kg/m3), and the top half is filled with oil (ρ = 0.85 x 103 kg/m3). Suppose that a rectangular block of wood of mass 5.5 kg, 30 cm long, 20 cm wide and 10 cm high is placed in this tank. How deep will the...

A beach ball is made of thin plastic. It has been inflated with air, but the plastic is not stretched. By swimming with fins on, you manage to take the ball from the surface of a pool to the bottom. Once the ball is completely submerged, what happens to the buoyant force exerted on the beach...

Buoyancy -- block of concrete is being raised from a lake Question; A 50kg block of concrete is being raised from a lake. What fraction of its weight in air is required to lift it while submerged? My attempt, I'm pretty sure this question pertains to Archimedes principle I calculated the...

1. At Lagoon, there is a large granite rock ball that is supported by water pressure, so people can spin the rock. The diameter of the rock is 1.3m. Granite has a density of 2691kg/m^3. Let’s assume a water pressure if 50 lbs/in^2. Calculate the area of the ball that must be in the water...

Homework Statement Very large air bags are used to lift instruments for high altitude measurements as shown in the image below. At ground level the bag is only partially filled with helium, just buoyant enough to rise. A) As the balloon rises, describe what happens to the magnitude of the...

Hello there, A weather balloon is released, and its acceleration in the z-x-plane, a is governed by a buoyancy force, B, which is constant in the k-direction. gravitational acceleration, 9.81 m/s^2, in the k-direction, and FD, which is is like this: F_D = -D|\vec{v}|\vec{v} where D is some...

Homework Statement The battleship Oklahoma was attached at Pearl Harbor by Japanese dive bombers. The ship was hit by multiple torpedoes and capsized (rolled 180 degrees so the bottom of the hull pointed straight up). The final orientation of the ship had 20 percent of its height above the...

I believe that I am making this a bit harder than it should be. An object is weighted so that it "hoovers" 5 feet underwater. It is neutrally buoyant. A diver drags the object even deeper without adding weight, she releases the object at a deepth of 100ft. Will the object stay put, rise up...

Imagine you are in an elevator accelerating downwards with acceleration g, holding a balloon (which would fly upwards if left outside). Now if the thread you are holding snaps, what will happen to the balloon? Since the acceleration felt inside the elevator is 0, the balloon should not...

I have a rather simple question which I can't seem to find an answer to If I have two balls, one denser than the other, but of same volume, and let them float on water, would the denser one float deeper in the water? The water is the same and the density of the two balls are less than the...

Homework Statement A cubical block of density ρb with sides lengths L floats in a liquid of greater density ρL. (A) what fraction of the blocks volume is above the surface of the liquid? (b) the liquid is denser than water (density ρw) and does not mix with it. If water is poured on the...

I am looking to calculate the center of buoyancy of a model blimp envelope. I have calculated various cross sections of the envelope to get the total volume (and thus the lift) and surface area. By center of buoyancy I mean the point that one could tie a string and add a weight and the...

Homework Statement For each statement, select the phrase that makes the statement true (e.g., if the answer to the first is A and to the others B, enter ABBBB): A) increases B) decreases C) less than D) greater than E) stays the same F) the same as A boat containing a cement...

Hello, if I were to suspend a rubber stopper into a graduated cylinder filled with water, with the stopper half in the h2o and half out of it, how would i calculate the tension in the string? Experimentally, i would collect the displaced volume, density (1000kg/m3), and mass of stopper. I am...

I am looking at building a machine that roams underwater, most always completely submerged. I would like at one point for the device to return to the surface and was wondering if it is possible to use electrolysis to turn the water into gas enough to provide buoyancy that would lift the machine...

Homework Statement A piece of wood floats in water with 65% of its volume under water.Find the relative density of the wood. Homework Equations Buoyancy = (Weight of object) / (Relative density of object) The Attempt at a Solution B = W/s 1= .65/s s = .65/1...

There's something that I don't understand about the buoyancy formula. Is the buoyancy defined by the density of the gas inside a balloon multiplied by the volume of the balloon and multiplied by the gravitational acceleration? Or Is the buoyancy defined by the density of the air...

I'm a bit lost getting started analyzing the following system, a pump of sorts: http://i.imgur.com/P82vtZ1.png It consists of a vertically-orientated tube submerged in water with heating elements around the middle. Heat energy goes in, causing a temperature difference which drives a...

I was having a discussion with a friend and we could not come to an agreement on the following: If you were to weigh yourself on a very sensitive set of scales, would you register the amount of air that you breathe in as an increase in measured weight? The way I see it is, you can make one...

Hi to all, i will appreciate your help in this. This is the situation: I have a tank, with a water column in it. This tank at the bottom has an "ideal" seal (a seal that permit the passing of object from bottom to upwards, but not the water to fall down.) In this system i have sphere with...

Homework Statement I want to find all acting forces on a hot air balloon rising form the ground. Volume and mass of balloon are given. Homework Equations F=mg F_{b}=ρVg The Attempt at a Solution Here is my free-body diagram; There are three acting forces: 1) F_1 = mg...

Homework Statement A raft is constructed of wood having a density of 625 kg/m^3. It's surface area is 5.5 m^2, and it's volume is 1.5 m^3. When the raft is placed in fresh water (denistiy = 1000 kg/m^3), to what depth, h, is the raft submerged under the water? Homework Equations P =...

The buoyancy force is defined as the difference in pressures on the top and bottom of an object submerged in a fluid. When an object is pushing on the top surface of a fluid from underneath, the force of surface tension begins to act downward on the object, preventing it from breaking the...

Homework Statement I have a balloon with a volume of 500m3 Outside air temp of 300K Mass to lift of 300kg Molar mass of air is 28 g/mol (I didn't end up using this) I am to find the temperature inside the balloon to barely lift the given mass. I have apparently forgotten everything...

A geode is a hollow rock with a solid shell and an air-filled interior. Suppose a particular geode weighs twice as much in air as it does when completely submerged in water. If the density of the solid part of the geode is 3100 km/m^3 , what fraction of the geode's volume is hollow? The...

Question: Suppose a person weighing 530 Newtons is floating in a salt lake (concentration of 20% NaCl) with a specific gravity of 1.148. How much less of the person's body would be in the salt water as compared to if he were floating in ordinary water (w/ density 1.00g/cm^3)? Comment: One...

Homework Statement A house has a roof with an area of 220 m2. Wind blows over the top with a speed of 10 m/s. The density of air is 1.29 kg/m2. The air inside the house is stagnant. Point A is just inside the roof, and point B is outside the roof at the same height. (a) What is the...

Homework Statement Consider a hose that carries water (density = 1000 kg/m3) leads to a nozzle that is elevated h = 1.3 meters above the ground. The nozzle has a diameter d, and the hose has a diameter D = 5d. Water flows through the hose with a speed vH = 0.6 m/s. (a) What is the...

Homework Statement A slab of ice floats on a freshwater lake. What minimum volume must the slab have for a 49 kg person to be able to stand on it without getting his or her feet wet? (use 920kg/m^3 as density of ice and 1000 kg/m^3 for the density of freshwater) Homework Equations...

Is this equation correct? equation 1: mass=density(density-density) Im asking this because in air correction we have equation 2: mass=density(density-density)/density(density-density) -----here we get mass.But get we mass still in this case?:mass=density(density-density) Because I was trying to...

Homework Statement I've attached the problem I'm kind of lost as to how to even start this problem. For part ) I think my first approach is to sum up forces in the vertical direction. Which would yield F-W1-W2=ma=0 Where: F=buoyancy force W1=weight of submerged volume of oak...

Homework Statement A plastic cube, 200mm x 200mm x 200mm, is left in a cylindrical container that has a diameter of 400mm holding sea water, density 1024kg/m^3. The level in the container increases by 30mm as the block floats. i) Find the mass and density of the cube. ii) Find the extra...

1. A slab of ice floats on a freshwater lake. What minimum volume must the slab have for a 45.0 kg woman to be able to stand on it without getting her feet wet? 2. Archimedes Principal as well as Newton's Second Law will be applied The Attempt at a Solution I know that the...

I had read that, according to Law of Buoyancy/Archimedes Principle, "Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object." But does that depend on the shape of the object immersed? I see, that a metal block...

I believe that T=PV-M. P is density of fluid surrounding the object, v is volume of object and M is the mass of object. So i have this object which is able to float due to air trapped inside it. This object is able to carry an extra load of 10 kg. So my formula would be, T= [p*(vol of...

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.

I've this to be handed in by tomorrow Please give some guidelines... I think that my working is completely wrong ! Homework Statement An empty cylinder bucket, 30cm in diameter and 50cm long, whose wall thickness and weight can be considered negligible is forced, open end first, into water...

I'm doing a project that requires a platform that is able to float up and down a water depth of 0-100m. It'll be pulled down by a fishing line. I'm currently using air as buoyant. This air will be trapped in a container. However there is air pressure at a certain water depth. The air will...

Homework Statement Styrofoam has a density of . What is the maximum mass that can hang without sinking from a 20.0 -diameter Styrofoam sphere in water? Assume the volume of the mass is negligible compared to that of the sphere. Homework Equations FB = ρfVg Fg = mg The Attempt at a...

Homework Statement An object suspended in water is lifted out of the water. How does the absolute pressure at the bottom of the water change? Homework Equations The Attempt at a Solution Wouldn't the absolute pressure not change if the object is still directly over the water...

Homework Statement 1. a 300kg object is placed upon a block of ice what volume of ice is needed to keep the object fully above water. 2. if the object density is .94gcm ^-3 what volume of the object remains above water on ice half the size. 3. What volume of the object remains above water...

Archimedes's principle says that the buoyancy force would be equal to the weight of the fluid displaced by the body. It's easy to work with the completely submerged object since I just need the whole volume of the object to as it is equal to the volume of displaced fluid. However, if an object...

Buoyancy, Volume, Mass..Please Help! a) If 2 boxes have the same apparent weight when submerged in stationary fresh water, and V1 (the volume of box 1) is greater than V2 (the volume of box 2) would the buoyancy of box 1 be greater than box 2 and masses be equal?? If not, would be relationship...

I'm trying to work through the below problem but it is a bit tricky and I would love any helpful tips: A boat with a lead block on it is sitting in a pool. On the side of the boat is a red line right at the water level. On the side of the pool is a blue line right at the water level. The...

1.) if there are two blocks of different masses rolling down an inclined plane, will their velocity be same? if so then how? there's no friction between the plane and the blocks. 2.) there is a plastic boat in a tub, filled with metal rods. if the metal rods are taken out of the boat and put...

Say that I have two objects of the same mass and volume. I place one into freshwater and another in glycerine. In both cases, the objects are floating. Would the buoyant force from both of these fluids acting on the object be the same? From my understanding, buoyant force measures the weight...

Could anyone suggest an online-reference about the basics? I'm trying to figure out whether there would be such buoyancy in a complicated situation.

Hi all, this is my first post. I was wondering if it would be possible to use a deflatable/inflatable bladder inside a housing with an air valve at the top and bottom of said bladder secured through the housing. The housing material would be heavy, placticised metal or stainless steel. This...