Exam 11: Static Fluids

A barge is 10 m wide and 60 m long and has vertical sides.The bottom of the boat is 1.2 m below the water surface.What is the weight of the barge and its cargo (force exerted on them by Earth),if it is floating in fresh water of density 1000 kg/m³?

A polar bear of mass 200 kg stands on an ice floe that is a uniform 1.0 m thick.What is the minimum area of the floe that will just support the bear in saltwater of density 1030 kg/m³? The density of ice is 980 kg/m³.

A crane lifts a steel submarine of density 7800 kg/m³ and mass 20,000 kg.What is the tension force that the lifting cable exerts on the submarine (a)when the submarine is submerged in water of density 1000 kg/m³,and (b)when it is entirely out of the water?

A spherical ball of lead (density 11.3 g/cm³)is placed in a tub of mercury (density 13.6 g/cm³).Which answer best describes the result?

A block of metal weighs 40 N in air and 30 N in water.What is the buoyant force that the water exerts on the block? The density of water is 1000 kg/m³.

A steel ball sinks in water but floats in a pool of mercury,which is much denser than water.Where is the buoyant force exerted on the ball by the liquid greater?

An object floats with half its volume beneath the surface of the water.The weight (force that Earth exerts in it)of the displaced water is 2000 N.What is the weight (force that Earth exerts on it)of the object? The density of water is 1000 kg/m³.

A wooden block contains some nails so that its average density is exactly equal to that of water.If it is placed in a tank of water and released from rest when it is completely submerged,it will

What buoyant force is exerted by water on a 0.60-kg solid gold crown when it is immersed in water? The density of gold is 19.3 × 10³ kg/m³ and that of water is 1000 kg/m³.

A barge with vertical sides is 10 m wide and 60 m long and is floating in fresh water of density 1000 kg/m³.How much deeper into the water does the barge sink when 3.0 x 10⁵ kg of coal are loaded on the barge?

A closed cubical chamber resting on the floor contains oil and a piston.If you push down on the piston hard enough to increase the pressure just below the piston by an amount Δp,which of the following statements is correct? (There could be more than one correct choice.)

The deepest point of the Pacific Ocean is 11,033 m,in the Mariana Trench.What is the gauge pressure in the water at that point? The density of seawater is 1025 kg/m³.

A cubical block of stone is lowered at a steady rate into the ocean by a crane,always keeping the top and bottom faces horizontal.Which one of the following graphs best describes the gauge pressure p on the bottom of this block as a function of time t if the block just enters the water at time t = 0 s?

A water tank is filled to a depth of 10 m,and the bottom of the tank is 20 m above ground.A water-filled hose that is 2.0 cm in diameter extends from the bottom of the tank to the ground,but no water is flowing in this hose.The water pressure at ground level in the hose is closest to which of the following values? The density of water is 1000 kg/m³.

A hollow steel ball of diameter 3.0 m just barely floats in water.What is the wall thickness of the ball? (ρ_Fe = 7.87 g/cm³, ρ_water = 1.00 g/cm³)

A circular window 30 cm in diameter in a submarine can withstand a net maximum force of 5.20 × 10⁵ N without damage.What is the maximum depth in a fresh-water lake to which the submarine can go without damaging the window? The density of fresh water is 1000 kg/m³.

The water company increased the water pressure in the water flowing to an apartment.The water enters the apartment through an entrance valve at the front of the apartment.Where will the increase in the static water pressure be greatest when no water is flowing in the system?

When a container of water is placed on a laboratory scale,the scale reads 120 g.Now a 20-g piece of copper (of density 8.9 g/cm³)is suspended from a thread and lowered into the water,not touching the bottom of the container.What will the scale now read? The density of water is 1.0 g/cm³.

A 200-kg flat-bottomed boat floats in fresh water,which has a density of 1000 kg/m³.If the base of the boat is 1.42 m wide and 4.53 m long,to what depth is the bottom of the boat submerged when it carries three passengers whose total mass is $257 \mathrm {~kg} \text { ? }$

A cubical block of stone is lowered at a steady rate into the ocean by a crane,always keeping the top and bottom faces horizontal.Which one of the following graphs best describes the absolute (total)pressure p on the bottom of this block as a function of time t if the block just enters the water at time t = 0 s?