Question 1

A 1.00-m3 object floats in water with 20.0% of its volume above the waterline.What is the force that Earth exerts on the object? The density of water is 1000 kg/m3.

Accepted Answer

A) 1,960 N 
B) 7,840 N 
C) 9,800 N 
D) 11,800 N 
A) 1,960 N 
B) 7,840 N 
C) 9,800 N 
D) 11,800 N

Question 2

A 10-kg piece of aluminum sits at the bottom of a lake,right next to a 10-kg piece of lead,which is much denser than aluminum.Which one has the greater buoyant force exerted on it by the water?

Accepted Answer

A) the aluminum 
B) the lead 
C) The same buoyant force is exerted on both. 
D) It cannot be determined without knowing their volumes. 
A) the aluminum 
B) the lead 
C) The same buoyant force is exerted on both. 
D) It cannot be determined without knowing their volumes.

Question 3

A 13,000-N vehicle is to be lifted by a 25-cm diameter hydraulic piston.What force needs to be exerted on a 5.0 cm diameter piston to accomplish this? Assume the pistons each have negligible mass.

Accepted Answer

A) 260 N 
B) 520 N 
C) 2600 N 
D) 5200 N 
A) 260 N 
B) 520 N 
C) 2600 N 
D) 5200 N

Question 4

Salt water has greater density than fresh water.A boat floats in both fresh water and in salt water.Where is the buoyant force exerted on the boat by the water greater?

Accepted Answer

A) in salt water 
B) in fresh water 
C) The buoyant force is the same in both cases. 
A) in salt water 
B) in fresh water 
C) The buoyant force is the same in both cases.

Question 5

A 4.0-kg cylinder of solid iron is supported by a string while submerged in water.What is the force that the string exerts on the cylinder? The density of iron is 7860 kg/m3 and that of water is 1000 kg/m3.

Accepted Answer

A) 2.5 N 
B) 20 N 
C) 24 N 
D) 34 N 
E) 40 N 
A) 2.5 N 
B) 20 N 
C) 24 N 
D) 34 N 
E) 40 N

Question 6

As shown in the figure,a large open tank contains a layer of oil ( density 450 kg/ $m ^ { 3 }$ )floating on top of a layer of water (density 1000 kg/m3)that is 3.0 m thick,as shown in the sketch.What must be the thickness of the oil layer if the gauge pressure at the bottom of the tank is to be $8.5 \times 10^4 \mathrm {~Pa} \text { ? }$

Accepted Answer

Question 7

The Tonga Trench in the Pacific Ocean is 36,000 feet deep.Assuming that sea water has an average density of 1.04 g/cm3,calculate the absolute (total)pressure at the bottom of the trench in atmospheres.(1.00 in = 2.54 cm,1.00 atm = 1.01 × 105 Pa)

Accepted Answer

A) 1.1 × 103 atm 
B) 1.1 × 108 atm 
C) 1.1 × 105 atm 
D) 1.1 × 106 atm 
E) 2.1 atm 
A) 1.1 × 103 atm 
B) 1.1 × 108 atm 
C) 1.1 × 105 atm 
D) 1.1 × 106 atm 
E) 2.1 atm

Question 8

The small piston of a hydraulic lift has a diameter of 8.0 cm,and its large piston has a diameter of 40 cm.The lift raises a load of 15,000 N.Assume the pistons each have negligible mass.
(a)Determine the force that must be exerted by the fluid in the lift on the small piston.
(b)Determine the pressure applied to the fluid in the lift.

Accepted Answer

(a)600 N

Question 9

A piece of wood is floating in a bathtub.A second piece of wood sits on top of the first piece,and does not touch the water.If the top piece is taken off and placed in the water,what happens to the water level in the tub?

Accepted Answer

A) It goes up. 
B) It goes down. 
C) It does not change. 
D) It cannot be determined without knowing the volumes of the two pieces of wood. 
A) It goes up. 
B) It goes down. 
C) It does not change. 
D) It cannot be determined without knowing the volumes of the two pieces of wood.

Question 10

A rectangular box of negligible mass measures 5.0 m long,1.0 m wide,and 0.50 m high.How many kilograms of material can be loaded onto the box before it sinks in a lake having water of density 1000 kg/m3?

Accepted Answer

A) 0.50 × 103 kg 
B) 1.5 × 103 kg 
C) 2.5 × 103 kg 
D) 3.5 × 103 kg 
A) 0.50 × 103 kg 
B) 1.5 × 103 kg 
C) 2.5 × 103 kg 
D) 3.5 × 103 kg

Question 11

A wooden raft has a mass of 55 kg.When empty it floats in water (density $\left. 1000 \mathrm {~kg} / \mathrm { m } ^ { 3 } \right)$ with 64% of its volume submerged.What maximum mass of sand can be put on the raft without sinking it?

Accepted Answer

The answer of A wooden raft has a mass of...

Question 12

A container consists of two vertical cylindrical columns of different diameter connected by a narrow horizontal section,as shown in the figure.The open faces of the two columns are closed by very light plates that can move up and down without friction.The tube diameter at A is 35.0 cm and at B it is 10.2 cm.This container is filled with oil of density 0.820 g/cm3.If a 125-kg object is placed on the larger plate at A,how much mass should be placed on the smaller plate at B to balance it?

Accepted Answer

Question 13

A rectangular wooden block measures 10.0 cm × 4.00 cm × 2.00 cm.When the block is placed in water,it floats horizontally,with its bottom face 1.65 cm below the surface.What is the density of the wood? The density of water is 1.00 g/cm3.

Accepted Answer

A) 0.825 g/cm3 
B) 1.21 g/cm3 
C) 1.65 g/cm3 
D) 0.606 g/cm3 
E) 0.350 g/cm3 
A) 0.825 g/cm3 
B) 1.21 g/cm3 
C) 1.65 g/cm3 
D) 0.606 g/cm3 
E) 0.350 g/cm3

Question 14

A piece of iron rests on top of a piece of wood floating in a bathtub.If the iron is removed from the wood,and kept out of the water,what happens to the water level in the tub?

Accepted Answer

A) It goes up. 
B) It goes down. 
C) It does not change. 
D) It is impossible to determine from the information given. 
A) It goes up. 
B) It goes down. 
C) It does not change. 
D) It is impossible to determine from the information given.

Question 15

The Aswan High Dam on the Nile River in Egypt is 111 m high.What is the gauge pressure in the water at the foot of the dam? The density of water is 1000 kg/m3.

Accepted Answer

A) 1.09 × 106 Pa 
B) 1.16 × 106 Pa 
C) 1.09 × 103 Pa 
D) 1.11 × 105 Pa 
E) 1.11 × 102 Pa 
A) 1.09 × 106 Pa 
B) 1.16 × 106 Pa 
C) 1.09 × 103 Pa 
D) 1.11 × 105 Pa 
E) 1.11 × 102 Pa

Question 16

A boat loaded with rocks is floating in a swimming pool.If the rocks are thrown into the pool,the water level in the pool,after the rocks have settled to the bottom,

Accepted Answer

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

Question 17

Consider a brick that is totally immersed in water,with the long edge of the brick vertical.The pressure on the brick is

Accepted Answer

A) the same on all surfaces of the brick. 
B) greatest on the face with largest area. 
C) greatest on the top of the brick. 
D) greatest on the sides of the brick. 
E) greatest on the bottom of the brick. 
A) the same on all surfaces of the brick. 
B) greatest on the face with largest area. 
C) greatest on the top of the brick. 
D) greatest on the sides of the brick. 
E) greatest on the bottom of the brick.

Question 18

You use a spring scale to suspend an object.The spring scale reads 7.84 N when the object is in air and 6.86 N when the object is immersed in water of density 1000 kg/m3.What is the density of the object?

Accepted Answer

A) 6000 kg/m3 
B) 7000 kg/m3 
C) 8000 kg/m3 
D) 9000 kg/m3 
A) 6000 kg/m3 
B) 7000 kg/m3 
C) 8000 kg/m3 
D) 9000 kg/m3

Question 19

If a ship has a mass of 10 million kilograms,what volume of fresh water must it displace in order to float? The density of water is 1000 kg/m3.

Accepted Answer

A) 1010 m3 
B) 1012 m3 
C) 104 m3 
D) 107 m3 
E) 108 m3 
A) 1010 m3 
B) 1012 m3 
C) 104 m3 
D) 107 m3 
E) 108 m3

Question 20

A 12,000-N car is raised using a hydraulic lift,which consists of a U-tube with arms of unequal areas,filled with oil with a density of 800 kg/m3 and capped at both ends with tight-fitting pistons.The wider arm of the U-tube has a radius of 18.0 cm and the narrower arm has a radius of 5.00 cm.The car rests on the piston on the wider arm of the U-tube.The pistons are initially at the same level.What is the force that oil must exert on the smaller piston in order to lift the car after it has been raised 1.20 m? For purposes of this problem,neglect the mass of the pistons.

Accepted Answer

A) 0.954 kN 
B) 1.88 kN 
C) 1.96 kN 
D) 3.67 kN 
E) 1.20 kN 
A) 0.954 kN 
B) 1.88 kN 
C) 1.96 kN 
D) 3.67 kN 
E) 1.20 kN

Exam 11: Static Fluids

A 1.00-m3 object floats in water with 20.0% of its volume above the waterline.What is the force that Earth exerts on the object? The density of water is 1000 kg/m3.

A 10-kg piece of aluminum sits at the bottom of a lake,right next to a 10-kg piece of lead,which is much denser than aluminum.Which one has the greater buoyant force exerted on it by the water?

A 13,000-N vehicle is to be lifted by a 25-cm diameter hydraulic piston.What force needs to be exerted on a 5.0 cm diameter piston to accomplish this? Assume the pistons each have negligible mass.

Salt water has greater density than fresh water.A boat floats in both fresh water and in salt water.Where is the buoyant force exerted on the boat by the water greater?

A 4.0-kg cylinder of solid iron is supported by a string while submerged in water.What is the force that the string exerts on the cylinder? The density of iron is 7860 kg/m3 and that of water is 1000 kg/m3.

The Tonga Trench in the Pacific Ocean is 36,000 feet deep.Assuming that sea water has an average density of 1.04 g/cm3,calculate the absolute (total)pressure at the bottom of the trench in atmospheres.(1.00 in = 2.54 cm,1.00 atm = 1.01 × 105 Pa)

A piece of wood is floating in a bathtub.A second piece of wood sits on top of the first piece,and does not touch the water.If the top piece is taken off and placed in the water,what happens to the water level in the tub?

A rectangular box of negligible mass measures 5.0 m long,1.0 m wide,and 0.50 m high.How many kilograms of material can be loaded onto the box before it sinks in a lake having water of density 1000 kg/m3?

A wooden raft has a mass of 55 kg.When empty it floats in water (density 1000 kg/m3)\left. 1000 \mathrm {~kg} / \mathrm { m } ^ { 3 } \right)1000 kg/m3) with 64% of its volume submerged.What maximum mass of sand can be put on the raft without sinking it?

A rectangular wooden block measures 10.0 cm × 4.00 cm × 2.00 cm.When the block is placed in water,it floats horizontally,with its bottom face 1.65 cm below the surface.What is the density of the wood? The density of water is 1.00 g/cm3.

A piece of iron rests on top of a piece of wood floating in a bathtub.If the iron is removed from the wood,and kept out of the water,what happens to the water level in the tub?

The Aswan High Dam on the Nile River in Egypt is 111 m high.What is the gauge pressure in the water at the foot of the dam? The density of water is 1000 kg/m3.

A boat loaded with rocks is floating in a swimming pool.If the rocks are thrown into the pool,the water level in the pool,after the rocks have settled to the bottom,

Consider a brick that is totally immersed in water,with the long edge of the brick vertical.The pressure on the brick is

You use a spring scale to suspend an object.The spring scale reads 7.84 N when the object is in air and 6.86 N when the object is immersed in water of density 1000 kg/m3.What is the density of the object?

If a ship has a mass of 10 million kilograms,what volume of fresh water must it displace in order to float? The density of water is 1000 kg/m3.

Introduction

Kinematics: Motion in One Dimension

Newtonian Mechanics

Applying Newtons Laws

Circular Motion

Impulse and Linear Momentum

Work and Energy

Extended Bodies at Rest

Rotational Motion

Gases

Fluids in Motion

First Law of Thermodynamics

Second Law of Thermodynamics

Electric Charge force and Energy

The Electric Field

Dc Circuits

Magnetism

Electromagnetic Induction

Vibrational Motion

Mechanical Waves

Reflection and Refraction

Mirrors and Lenses

Wave Optics

Electromagnetic Waves

Special Relativity

Quantum Optics

Atomic Physics

Nuclear Physics

Particle Physics

Filters

A 1.00-m³ object floats in water with 20.0% of its volume above the waterline.What is the force that Earth exerts on the object? The density of water is 1000 kg/m³.

A 4.0-kg cylinder of solid iron is supported by a string while submerged in water.What is the force that the string exerts on the cylinder? The density of iron is 7860 kg/m³ and that of water is 1000 kg/m³.

The Tonga Trench in the Pacific Ocean is 36,000 feet deep.Assuming that sea water has an average density of 1.04 g/cm³,calculate the absolute (total)pressure at the bottom of the trench in atmospheres.(1.00 in = 2.54 cm,1.00 atm = 1.01 × 10⁵^Pa)

A rectangular box of negligible mass measures 5.0 m long,1.0 m wide,and 0.50 m high.How many kilograms of material can be loaded onto the box before it sinks in a lake having water of density 1000 kg/m³?

A wooden raft has a mass of 55 kg.When empty it floats in water (density $\left. 1000 \mathrm {~kg} / \mathrm { m } ^ { 3 } \right)$ with 64% of its volume submerged.What maximum mass of sand can be put on the raft without sinking it?

A rectangular wooden block measures 10.0 cm × 4.00 cm × 2.00 cm.When the block is placed in water,it floats horizontally,with its bottom face 1.65 cm below the surface.What is the density of the wood? The density of water is 1.00 g/cm³.

The Aswan High Dam on the Nile River in Egypt is 111 m high.What is the gauge pressure in the water at the foot of the dam? The density of water is 1000 kg/m³.

You use a spring scale to suspend an object.The spring scale reads 7.84 N when the object is in air and 6.86 N when the object is immersed in water of density 1000 kg/m³.What is the density of the object?

If a ship has a mass of 10 million kilograms,what volume of fresh water must it displace in order to float? The density of water is 1000 kg/m³.