Halliday/Resnick/Walker Fundamentals of Physics 8th edition

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Halliday/Resnick/WalkerFundamentals of Physics
8th edition

• Classroom Response System Questions

Chapter 6 Force and Motion II
Reading Quiz Questions
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6.2.1. Which one of the following statements
concerning the static and kinetic frictional
forces is correct? a) When an object is
stationary, both static and kinetic frictional
forces are acting on it. b) When an object is
stationary, only the kinetic frictional force
acts on it. c) When an object is sliding, only
the static frictional force acts on it. d) The
static frictional force acts on an object when it
is stationary and the kinetic frictional force
acts on it when it is sliding. e) Static and
kinetic frictional forces act in the same
direction as the normal force.
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6.2.1. Which one of the following statements
concerning the static and kinetic frictional
forces is correct? a) When an object is
stationary, both static and kinetic frictional
forces are acting on it. b) When an object is
stationary, only the kinetic frictional force
acts on it. c) When an object is sliding, only
the static frictional force acts on it. d) The
static frictional force acts on an object when it
is stationary and the kinetic frictional force
acts on it when it is sliding. e) Static and
kinetic frictional forces act in the same
direction as the normal force.
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6.2.2. Which of the following is not one of the
properties of the friction force? a) There is
no upper limit to the magnitude of a static
friction force. b) The friction force on a
moving object is smaller than the friction force
on a stationary object. c) If an object is at
rest while a force is applied to the object
parallel to the surface on which its resting,
then the friction force on the object is equal in
magnitude to the applied force, but oppositely
directed. d) The friction force on an object
depends on the normal force acting on it. e) If
an object is sliding along a surface, the
friction force acts in the direction opposite to
the objects velocity.
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6.2.2. Which of the following is not one of the
properties of the friction force? a) There is
no upper limit to the magnitude of a static
friction force. b) The friction force on a
moving object is smaller than the friction force
on a stationary object. c) If an object is at
rest while a force is applied to the object
parallel to the surface on which its resting,
then the friction force on the object is equal in
magnitude to the applied force, but oppositely
directed. d) The friction force on an object
depends on the normal force acting on it. e) If
an object is sliding along a surface, the
friction force acts in the direction opposite to
the objects velocity.
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6.2.3. What is the underlying physical reason for
the difference between the static and kinetic
coefficients of friction of ordinary
surfaces? a) The static friction coefficient is
due to the presence of cold welds. b) There are
fewer cold welds in the case of sliding. c) In
the static case, nearly 100 of the surfaces are
in contact at the atomic level. d) When the two
surfaces are stationary relative to each other,
there are fewer cold welds.
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6.2.3. What is the underlying physical reason for
the difference between the static and kinetic
coefficients of friction of ordinary
surfaces? a) The static friction coefficient is
due to the presence of cold welds. b) There are
fewer cold welds in the case of sliding. c) In
the static case, nearly 100 of the surfaces are
in contact at the atomic level. d) When the two
surfaces are stationary relative to each other,
there are fewer cold welds.
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6.3.1. Two identical blocks are pulled along a
rough surface as suggested in the figure. Which
one of the following statements is
false? a) The coefficient of kinetic
friction is the same in each case. b) A force
of the same magnitude is needed to keep each
block moving. c) The normal force exerted on
the blocks by the surface is the same for both
blocks. d) The magnitude of the force of
kinetic friction is greater for the block on the
right. e) A force of the same magnitude was
required to start each block moving.
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6.3.1. Two identical blocks are pulled along a
rough surface as suggested in the figure. Which
one of the following statements is
false? a) The coefficient of kinetic
friction is the same in each case. b) A force
of the same magnitude is needed to keep each
block moving. c) The normal force exerted on
the blocks by the surface is the same for both
blocks. d) The magnitude of the force of
kinetic friction is greater for the block on the
right. e) A force of the same magnitude was
required to start each block moving.
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6.3.2. A block is pulled at constant speed along
a rough level surface by a rope that makes an
angle ? with respect to the horizontal. The
applied force along the rope is . The force
of kinetic friction between the block and the
surface is . Which one of the following
actions will increase the frictional force on the
block? a) increasing the angle made by the
rope b) decreasing the speed of the block c)
decreasing the contact surface area d)
increasing the contact surface area e)
increasing the weight of the block
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6.3.2. A block is pulled at constant speed along
a rough level surface by a rope that makes an
angle ? with respect to the horizontal. The
applied force along the rope is . The force
of kinetic friction between the block and the
surface is . Which one of the following
actions will increase the frictional force on the
block? a) increasing the angle made by the
rope b) decreasing the speed of the block c)
decreasing the contact surface area d)
increasing the contact surface area e)
increasing the weight of the block
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6.3.3. A brick is resting on the surface of a
flat board. As one end of the board is slowly
raised, what changes, if any, are there in the
normal force and in frictional forces exerted on
the brick? a) The normal force increases as
the frictional force increases. b) The normal
force decreases as the frictional force
increases. c) The normal force remains constant
as the frictional force increases. d) Only the
direction of the normal force changes as the
direction of the frictional force changes. e)
The normal force decreases and the frictional
force remains constant.
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6.3.3. A brick is resting on the surface of a
flat board. As one end of the board is slowly
raised, what changes, if any, are there in the
normal force and in frictional forces exerted on
the brick? a) The normal force increases as
the frictional force increases. b) The normal
force decreases as the frictional force
increases. c) The normal force remains constant
as the frictional force increases. d) Only the
direction of the normal force changes as the
direction of the frictional force changes. e)
The normal force decreases and the frictional
force remains constant.
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6.3.4. A brick is resting on the surface of a
flat board. One end of the board is slowly
raised. The brick begins sliding down the board
when it makes an angle ? with respect to the
horizontal plane. Which of the following give
the correct expression of the coefficient of
friction in this situation? a) mg sin ? b) mg
cos ? c) sin ? d) cos ? e) tan ?
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6.3.4. A brick is resting on the surface of a
flat board. One end of the board is slowly
raised. The brick begins sliding down the board
when it makes an angle ? with respect to the
horizontal plane. Which of the following give
the correct expression of the coefficient of
friction in this situation? a) mg sin ? b) mg
cos ? c) sin ? d) cos ? e) tan ?
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6.4.1. The drag force is not dependent on which
of the following parameters? a) air density b)
the drag coefficient c) the speed of the
object relative to the fluid in which its
moving d) the terminal velocity e)
cross-sectional area
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6.4.1. The drag force is not dependent on which
of the following parameters? a) air density b)
the drag coefficient c) the speed of the
object relative to the fluid in which its
moving d) the terminal velocity e)
cross-sectional area
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6.4.2. Which one of the following has the largest
terminal velocity? a) raindrop b) tennis
ball c) ping pong ball d) parachutist with an
open chute e) a shot put ball
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6.4.2. Which one of the following has the largest
terminal velocity? a) raindrop b) tennis
ball c) ping pong ball d) parachutist with an
open chute e) a shot put ball
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6.4.3. The terminal velocity is not dependent on
which one of the following properties? a) the
force of gravity b) air density c) the
falling time d) cross-sectional area e) the
drag coefficient
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6.4.3. The terminal velocity is not dependent on
which one of the following properties? a) the
force of gravity b) air density c) the
falling time d) cross-sectional area e) the
drag coefficient
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6.5.1. When using the term uniform circular
motion, what do we mean by the term
uniform? a) The direction of the objects
velocity is constant. b) The net force on the
moving object is zero newtons. c) The forces
acting on the object are uniformly applied from
all directions. d) The motion occurs without
the influence of the gravitational force. e)
The motion of the object is at a constant speed.
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6.5.1. When using the term uniform circular
motion, what do we mean by the term
uniform? a) The direction of the objects
velocity is constant. b) The net force on the
moving object is zero newtons. c) The forces
acting on the object are uniformly applied from
all directions. d) The motion occurs without
the influence of the gravitational force. e)
The motion of the object is at a constant speed.
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6.5.2. If an object is moving in uniform circular
motion, its period is given by which one of the
following quantities? a) the speed of the
object b) the centripetal acceleration of the
object c) the number of revolutions the object
makes each second d) the time interval for the
object to make one revolution e) the
displacement of the object
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6.5.2. If an object is moving in uniform circular
motion, its period is given by which one of the
following quantities? a) the speed of the
object b) the centripetal acceleration of the
object c) the number of revolutions the object
makes each second d) the time interval for the
object to make one revolution e) the
displacement of the object
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6.5.3. A bicycle racer is traveling at constant
speed v around a circular track. The centripetal
acceleration of the bicycle is ac. What happens
to the centripetal acceleration of the bicycle if
the speed is doubled to 2v? a) The centripetal
acceleration increases to 4ac. b) The
centripetal acceleration decreases to 0.25ac. c)
The centripetal acceleration increases to
2ac. d) The centripetal acceleration decreases
to 0.5ac. e) The centripetal acceleration does
not change.
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6.5.3. A bicycle racer is traveling at constant
speed v around a circular track. The centripetal
acceleration of the bicycle is ac. What happens
to the centripetal acceleration of the bicycle if
the speed is doubled to 2v? a) The centripetal
acceleration increases to 4ac. b) The
centripetal acceleration decreases to 0.25ac. c)
The centripetal acceleration increases to
2ac. d) The centripetal acceleration decreases
to 0.5ac. e) The centripetal acceleration does
not change.
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6.5.4. A satellite orbits the Earth in uniform
circular motion. What is the direction of
centripetal acceleration of the satellite? a)
The centripetal acceleration is a scalar quantity
and it doesnt have a direction. b) The
centripetal acceleration vector points radially
outward from the Earth. c) The centripetal
acceleration vector points radially inward toward
the Earth. d) The centripetal acceleration
vector points in the direction of the satellites
velocity. e) The centripetal acceleration
vector points in the direction opposite that of
the satellites velocity.
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6.5.4. A satellite orbits the Earth in uniform
circular motion. What is the direction of
centripetal acceleration of the satellite? a)
The centripetal acceleration is a scalar quantity
and it doesnt have a direction. b) The
centripetal acceleration vector points radially
outward from the Earth. c) The centripetal
acceleration vector points radially inward toward
the Earth. d) The centripetal acceleration
vector points in the direction of the satellites
velocity. e) The centripetal acceleration
vector points in the direction opposite that of
the satellites velocity.
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6.5.5. A motorcycle travels at a constant speed
around a circular track. Which one of the
following statements about this motorcycle is
true? a) The car has a velocity vector that
points along the radius of the circle. b) The
car is characterized by constant velocity. c)
The car is characterized by constant
acceleration. d) The velocity of the car is
changing. e) The car has an acceleration vector
that is tangent to the circle at all times.
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6.5.5. A motorcycle travels at a constant speed
around a circular track. Which one of the
following statements about this motorcycle is
true? a) The car has a velocity vector that
points along the radius of the circle. b) The
car is characterized by constant velocity. c)
The car is characterized by constant
acceleration. d) The velocity of the car is
changing. e) The car has an acceleration vector
that is tangent to the circle at all times.
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6.5.6. The centripetal force is best explained by
which of the following statements? a) The
centripetal force is the force on an object that
is directed radially outward from the center of
its orbit. b) The centripetal force is the
force on an orbiting object that is directed
along a line that is tangent to the circle. c)
The centripetal force is the net force acting on
an orbiting object that maintains it in uniform
circular motion. d) The centripetal force is a
fundamental force of nature.
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6.5.6. The centripetal force is best explained by
which of the following statements? a) The
centripetal force is the force on an object that
is directed radially outward from the center of
its orbit. b) The centripetal force is the
force on an orbiting object that is directed
along a line that is tangent to the circle. c)
The centripetal force is the net force acting on
an orbiting object that maintains it in uniform
circular motion. d) The centripetal force is a
fundamental force of nature.
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6.5.7. Which one of the following forces holds a
car on a frictionless banked curve? a) the
horizontal component of the normal force b)
the vertical component of the car's weight c)
the vertical component of the normal force d)
the horizontal component of the car's weight e)
the reaction force to the car's weight
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6.5.7. Which one of the following forces holds a
car on a frictionless banked curve? a) the
horizontal component of the normal force b)
the vertical component of the car's weight c)
the vertical component of the normal force d)
the horizontal component of the car's weight e)
the reaction force to the car's weight