Deck 13: Liquids

Question 1

Use the following figure to answer the question:
A dam is thicker at the bottom than at the top partly because

A)water is denser at deeper levels.
B)water pressure is greater with increasing depth.
C)surface tension exists only on the surface of liquids.
D)it looks better.
E)none of these

Answer 1

water pressure is greater with increasing depth.

Question 2

The reason that buoyant force acts upward on a submerged object is that

A)it acts in a direction to oppose gravity.
B)if it acted downward,nothing would float.
C)the weight of fluid displaced reacts with an upward force.
D)upward pressure against the bottom is greater than downward pressure against the top of the submerged object.

Answer 2

upward pressure against the bottom is greater than downward pressure against the top of the submerged object.

Question 3

Pumice is a volcanic rock that floats.Its density is

A)less than the density of water.
B)equal to the density of water.
C)more than the density of water.

Answer 3

less than the density of water.

Question 4

The buoyant force on a rock is least when the rock is submerged

A)near the surface.
B)halfway to the bottom.
C)near the bottom.
D)Buoyant force does not depend on depth.

Question 5

When an object is partly or wholly immersed in a liquid,it is buoyed up

A)by a force equal to its own weight.
B)by a force equal to the weight of liquid displaced.
C)and floats because of Archimedes principle.
D)but nevertheless sinks.
E)none of these

Question 6

The pressure at the bottom of a jug filled with water does NOT depend on

A)the acceleration due to gravity.
B)water density.
C)the height of the liquid.
D)surface area of the water.
E)none of these

Question 7

Blood pressure is normally greater in your

A)ears.
B)feet.
C)same in each

Question 8

Lobsters live on the bottom of the ocean.The density of a lobster is

A)greater than the density of sea water.
B)equal to the density of sea water.
C)less than the density of sea water.

Question 9

The mass of a cubic meter of water is

A)1 kg.
B)10 kg.
C)100 kg.
D)1000 kg.
E)9800 N.

Question 10

What is the buoyant force acting on a 10-ton ship floating in the ocean?

A)less than 10 tons
B)10 tons
C)more than 10 tons
D)depends on density of sea water

Question 11

Water pressure is greatest against the

A)top of a submerged object.
B)bottom of a submerged object.
C)sides of a submerged object.
D)is the same against all surfaces
E)none of these

Question 12

A fish normally displaces its own

A)volume of water.
B)weight of water.
C)both of these
D)neither of these

Question 13

When holes are drilled through the wall of a water tower ,water will spurt out the greatest horizontal distance from the hole closest to

A)the bottom of the tower.
B)the middle of the tower.
C)the top of the tower.
D)The horizontal distance will be the same for all holes.

Question 14

What is the weight of water displaced by a 100-ton floating ship?

A)less than 100 tons
B)100 tons
C)more than 100 tons
D)100 cubic meters
E)depends on the ship's shape

Question 15

A completely submerged object always displaces its own

A)volume of fluid.
B)weight of fluid.
C)density of fluid.
D)all of these
E)none of these

Question 16

The reason a life jacket helps you float is

A)the jacket makes you weigh less.
B)the jacket has the same density as an average human.
C)the jacket repels water.
D)if you sink,the jacket sinks.
E)the density of both you and the jacket together is less than your density alone.

Question 17

The buoyant force on an object is least when the object is

A)partly submerged.
B)submerged near the surface.
C)submerged near the bottom.
D)none of these

Question 18

Compared to the density of water,the density of a fish is

A)more.
B)less.
C)the same.

Question 19

One liter of water has a mass of

A)1 kilogram.
B)14.7 grams.
C)500 grams.
D)none of the above choices

Question 20

The pressure in a liquid depends on liquid

A)density.
B)depth.
C)both of these
D)neither of these

Question 21

A heavy glass ball is placed in a pie pan that floats in a bucket.The water level at the side of the bucket is marked.Then the glass ball is removed and allowed to sink in the bucket.The water line at the side of the bucket is now

A)lower.
B)the same.
C)higher.

Question 22

The volume of water displaced by a floating 20-ton boat

A)is 20 cubic meters.
B)is the volume of 20 tons of water.
C)is the volume of the boat.
D)depends on the shape of the ship's hull.
E)none of these

Question 23

Ice cubes submerged at the bottom of a liquid indicate that the liquid

A)produces no buoyant force on the ice.
B)has dissolved air.
C)is warmer than the ice.
D)is not displaced by the submerged ice.
E)is less dense than ice.

Question 24

Compared to the buoyant force that acts on you when you float in fresh water,the buoyant force that acts on you when you float in the dense water of the Dead Sea is

A)less,because less of your volume is displaced.
B)more,because of the greater density of fluid displaced.
C)the same.

Question 25

A lobster crawls onto a bathroom scale submerged at the bottom of the ocean.Compared to its weight above the surface,the lobster will have an apparent weight under water that is

A)greater.
B)less.
C)the same.

Question 26

A block of wood weighing 5 N in air,is difficult to fully submerge in a pool of mercury because the buoyant force when fully submerged is

A)less than 5 N.
B)5 N.
C)much more than 5 N.

Question 27

Buoyant force is greatest on a submerged

A)1-cubic centimeter block of lead.
B)1-cubic centimeter block of aluminum.
C)is the same on each

Question 28

Compared to an empty ship,the same ship loaded with Styrofoam will float

A)higher in the water.
B)lower in the water.
C)at the same level in the water.

Question 29

The density of a submerged submarine is about the same as the density of

A)a crab.
B)iron.
C)a floating submarine.
D)water.
E)none of these

Question 30

Buoyant force is greatest on a submerged

A)1-kg block of lead.
B)1-kg block of aluminum.
C)is the same on each

Question 31

An egg is placed at the bottom of a bowl filled with water.Salt is slowly added to the water until the egg rises and floats.From this experiment,one concludes

A)calcium in the egg shell is repelled by sodium chloride.
B)the density of salt water exceeds the density of egg.
C)buoyant force does not always act upward.
D)salt sinks to the bottom.

Question 32

Buoyant force is greatest on a submerged

A)10-newton block of lead.
B)10-newton block of aluminum.
C)is the same on each

Question 33

A boat loaded with scrap iron floats in a swimming pool.When the iron is thrown overboard,the pool level will

A)rise.
B)fall.
C)remain unchanged.

Question 34

A block of Styrofoam floats on water while a same size block of lead lies submerged in the water.The buoyant force is greatest on the

A)lead.
B)Styrofoam.
C)is the same for both

Question 35

A liter-sized block of ordinary wood floats in water.The amount of water displaced is

A)less than 1 liter.
B)1 liter.
C)more than 1 liter.
D)depends on the water density
E)none of these

Question 36

Two life preservers have identical volumes,but one is filled with Styrofoam while the other is filled with sand.When the two life preservers are fully submerged,the buoyant force is greater on the one filled with

A)Styrofoam.
B)sand.
C)same on each as long as their volumes are the same

Question 37

A rock suspended by a string weighs 5 N out of water and 3 N when submerged.What is the buoyant force on the rock?

A)8 N
B)5 N
C)3 N
D)2 N
E)none of these

Question 38

Two life preservers have identical volumes,but one is filled with Styrofoam while the other is filled with sand.When the two life preservers are worn by swimmers so that one swimmer floats with part of the preserver above water,and the other swimmer sinks,the buoyant force is actually greater on the life preserver filled with

A)Styrofoam.
B)sand.
C)same

Question 39

Two equal sized buckets are filled to the top with water.One of the buckets has a piece of wood floating in it,making its total weight

A)less than the weight of the other bucket.
B)equal to the weight of the other bucket.
C)more than the weight of the other bucket.

Question 40

When you float in fresh water,the buoyant force that acts on you is equal to your weight.When you float higher in the high-density water of the Dead Sea,the buoyant force that acts on you is

A)greater than your weight.
B)less than your weight.
C)equal to your weight.

Question 41

A block of wood half as dense as water floats with half its volume above water.A piece of iron is then tied on top so the wood floats with only 1/4 its volume above the surface.If the wood and iron are turned over so that the iron is submerged beneath the wood,then the volume of wood above the water surface will be

A)more than 1/4.
B)less than 1/4.
C)the same,1/4.
D)There's no way to say.

Question 42

If a weighted air-filled balloon sinks in deep water,it will

A)likely sink to an equilibrium level before reaching bottom.
B)likely burst if water pressure is great enough.
C)become less dense as it sinks.
D)be acted on by a continuously decreasing buoyant force.
E)none of these

Question 43

In a hydraulic-press operation,it is impossible for the

A)output displacement to exceed the input displacement.
B)force output to exceed the force input.
C)energy output to exceed the energy input.
D)output piston's speed to exceed the input piston's speed.
E)none of these

Question 44

To multiply the input force of a hydraulic lift ,the input end should be the one having the

A)larger diameter piston.
B)smaller diameter piston.
C)Relative piston sizes don't matter.

Question 45

When an ice cube in a glass of water melts,the water level

A)rises.
B)falls.
C)remains the same.

Question 46

A floating ice cube contains small pieces of iron.During melting the water level will

A)rise.
B)fall.
C)remain unchanged.

Question 47

If the part of an iceberg that extends above the water were suddenly removed,the

A)iceberg would sink.
B)buoyant force on the iceberg would decrease.
C)density of the iceberg would change.
D)pressure on the bottom of the iceberg would increase.
E)none of these

Question 48

There is a legend of a Dutch boy who bravely held back the Atlantic Ocean by plugging a leak near the top of a dike with his finger until help arrived.Which of the following is most likely?

A)The huge size of the Atlantic Ocean makes this impossible.
B)Although the force on his finger would have been huge,the pressure would have been small enough for this to occur.
C)The force on his finger would have been less than 1 N.
D)Both the force and pressure on his finger would have been great,but not too great for a public-spirited Dutch lad.
E)none of these

Question 49

A boat loaded with wood floats in a swimming pool.When the wood is thrown overboard,the pool level will

A)rise.
B)fall.
C)remain unchanged.

Question 50

A block of wood with a piece of iron tied to the top of it floats in a bucket of water.If the wood and iron are turned over so that the iron is submerged beneath the wood,the water level at the side of the bucket

A)rises.
B)falls.
C)remains the same.

Question 51

An ice cube floating in a glass of water contains many air bubbles.When the ice melts,the water level will

A)rise.
B)fall.
C)remain unchanged.

Question 52

A consequence of the surface tension of water is

A)capillary action.
B)wet sand's being firmer than dry sand.
C)that hot oily soup tastes different from cold oily soup.
D)all of these
E)none of these

Question 53

The ratio of output force to input force of a hydraulic press will be equal to the ratio of the output and input piston

A)diameters.
B)areas.
C)radii.
D)all of these
E)none of these

Question 54

A row boat containing a barrel of water floats in a swimming pool.When the water in the barrel is poured overboard,the swimming pool level will

A)rise.
B)fall.
C)remain unchanged.

Question 55

If a battleship sinks in a canal lock,the water level in the lock will

A)rise.
B)fall.
C)remain unchanged.

Question 56

Three icebergs are each floating in bathtubs filled to the brim with water.Iceberg A has large air bubbles in it.Iceberg B has unfrozen water in it.Iceberg C has an iron railroad spike in it.When the ice melts,what happens?

A)The water level in C will decrease while the other two water levels will remain the same.
B)Only the water in C will spill over.
C)The water level in A will stay the same,while the other tubs will spill over.
D)All the tubs spill over.
E)All stay exactly the same.

Question 57

A scale from which a rock is suspended reads 5 N when the rock is out of water and 3 N when the rock is submerged.The density of the rock is

A)the density of water.
B)1)5 times the density of water.
C)2)5 times the density of water.
D)3)5 times the density of water.

Question 58

A hydraulic press multiplies a force by 100.This multiplication is done at the expense of

A)energy,which is divided by 100.
B)the distance through which the force acts.
C)the time through which the force acts,which is multiplied by 100.
D)the mechanism providing the force.
E)none of these

Question 59

When a boat sails from fresh water to salt water,the boat will float

A)lower in the water.
B)higher in the water.
C)at the same water level.

Question 60

The pascal is a pressure unit equal to one

A)newton per square meter.
B)kilogram per square meter.
C)newton per square centimeter.
D)kilogram per square centimeter.
E)square meter per newton.

Question 61

A very light-weight horizontal loop of wire is suspended from a fine spring,lowered into water,and then raised to the surface.Any further attempt to raise it causes the spring to

A)stretch.
B)contract.
C)stay the same.

Question 62

Surface tension is a direct result of

A)viscosity.
B)Archimedes' principle.
C)Bernoulli's principle.
D)adhesive forces between molecules in a liquid or solid.
E)cohesive forces between molecules in a liquid.

Question 63

Surface tension of liquids

A)increases when wetting agents are added.
B)decreases as the liquid temperature increases.
C)is about the same for all liquids.
D)results from a thin molecular membrane beneath the liquid surface.
E)is the reason a steel ship will float.

Question 64

When you put a stick in water and remove it,the stick is wet.When you put a stick in mercury and remove it,the stick is dry.The reason for this is that adhesive forces are greater

A)between stick and water.
B)between the stick and mercury.
C)between the mercury and the water.