Physics Exam 2 Quizzes

The tendency of an object to resist a change in its motion is known as

Inertia

The gravitational force of the Earth on an object close to the surface is known as

Weight

The normal force is

The force of a surface on an object perpendicular to the surface

The acceleration of an object has what kind of relation to the force applied?

Linear

Which of these is a part of the definition of a force?

A push or a pull

Acts on an object

Requires an agent to create the force

All of these are correct

All of these are correct

Newton's first law says

An object's velocity will be constant (both speed and direction) as long as no force acts on it.

The acceleration of an object has what kind of relation to the mass of the object?

Inverse

The frictional force is

Parallel to the surface the object is on

Dynamics, or the study of forces, is the study of

The causes of motion

The symbol used for a frictional force is

f

Newton's 3rd law says

All forces occur as a part of an action/reaction pair

The force each object in a reaction pair experiences depends on the mass of the object

2 forces on 2 different objects cancel

The net force on any object is zero.

All forces occur as a part of an action/reaction pair

Which of these is not a unit of force?

Newton

Pound

(kg m)/sec2

All of these are units of force

All of these are units of force

How are acceleration and force related?

Acceleration is equal to force

Acceleration is inversely

proportional to force

Acceleration has no relation to force

Acceleration is directly proportional to force

Acceleration is directly proportional to force

If the net force on an object is zero, what can be said about the vectors on a free body diagram

The vector sum is zero

All of the vectors point in the direction of the acceleration

The vector sum points up

There are no vectors

The vector sum is zero

The net force on an object is

The sum of only the vertical forces on an object

Always zero

The vector sum of all the forces on the object

The scalar sum of all the forces on the object

The vector sum of all the forces on the object

An example of a long-range force is

Weight

Friction

Tension

Normal

Weight

The net force on an object is

In the same direction as the acceleration

Is in the opposite direction as the acceleration

Not related to the acceleration

Perpendicular to the acceleration

In the same direction as the acceleration

The other force in the action/reaction pair of a hammer striking a nail in a wall is

None of these.

The force of the nail on the hammer

The force of the wall on the nail

The force of the nail on the wall

The force of the nail on the hammer

A free body diagram should include

A coordinate system

The object represented as a dot

All forces represented as vectors

All of these

All of these

When a cat jumps from the floor onto a table, what can be said about the force on the floor

The force of the floor on the cat is less than the force of the cat on the floor

The force of the floor on the cat is greater than the force of the cat on the floor

The force of the floor on the cat is equal to the force of the cat on the floor

There is no force on the floor. The floor doesn't move.

The force of the floor on the cat is equal to the force of the cat on the floor

How can the apparent weight of on object be measured?

Only with special equipment

A simple scale

Apparent weight is not real and can't be measured

There is no known way to measure apparent weight.

A simple scale

How are the mass (m) and weight (w) of an object related?

m = wg

They are the same thing

w = m/g

w = mg

w = mg

The y component of an object's acceleration is determined by

All forces regardless of direction

The y components of all of the forces

The x components of all of the forces

Only gravity

The y components of all of the forces

The acceleration in the x-direction is determined by the

Sum of the x-components of all forces acting on the object

Sum of forces that are only in the x-direction acting on the object

Largest force on the object

Sum of x and y components of all forces on the object

Sum of the x-components of all forces acting on the object

If an object is in equilibrium, what does Newton's 2nd law tell us?

The net force is in the direction of motion

The net force is zero.

The net force is in the opposite direction as the motion

The net force is perpendicular to the motion

The net force is zero

Is the net force larger when an object is in static equilibrium or dynamic equilibrium

Depends on the mass of the object

Dynamic equilibrium

Static equilibrium

Net force for both is zero.

Net force for both is zero.

What can be said about the net force on an object when its velocity is changing?

Net force is zero

The net force is perpendicular to the acceleration.

Net force is in the same direction as the acceleration.

The net force must be changing as well.

Net force is in the same direction as the acceleration.

An object near the Earth is weightless if

The net force on it is zero

There are no forces on it

It is in free fall

It is too light to be weighed

It is in free fall

An object in dynamic equilibrium is

Moving with a constant velocity

Moving with a constant acceleration

Moving with a constant speed but changing direction

Stationary

Moving with a constant velocity

When is your weight different than your apparent weight?

When an elevator starts moving up

When an elevator comes to a stop

When an elevator starts moving down

None of these

All of the above

All of the above

The normal force is always

Less than the weight

Perpendicular to the weight

Equal to the weight

Perpendicular to the surface

Perpendicular to the surface

In order for a bicycle wheel to roll on the street the bottom of the wheel must

Experience a larger normal force

Experience no friction

Experience kinetic friction

Be stationary

Be stationary

How does the coefficient of static friction usually compare to the coefficient of kinetic friction?

Static = kinetic

Static < kinetic

Static > kinetic

No relation between the two.

Static > kinetic

The Reynolds number is used to characterize

The acceleration an object experiences

The type of friction between two solid surfaces

The types of force exerted by gravity

The types of drag an object experiences

The types of drag an object experiences

Is the normal force affected by any other forces?

Only when there is no friction.

No, it is only due to the surface.

Yes, it is changed by forces that are perpendicular to the normal force

Yes, it is changed by forces that are parallel to the normal force.

Yes, it is changed by forces that are parallel to the normal force.

Which of these does the kinetic frictional force not depend on?

Material of the object

Speed of the motion

Normal force on the object

Material of the surface

Speed of the motion

Terminal speed occurs when

The drag force is perpendicular to the acceleration

The drag force is equal in magnitude to the weight

The drag force is equal to the acceleration

The drag force is less than the weight

The drag force is equal in magnitude to the weight

When trying to slide an object on a rough surface, what requires a larger force?

There is no general trend.

Getting it started

It is the same force for starting it and continuing its motion

Keeping it going

Getting it started

Drag on an object moving through a fluid depends on

Inertial force of the fluid

Speed of the object

All of these

Viscous force of the fluid

All of these

The kinetic frictional force is proportional to

The width of the object.

The normal force on the object

The height of the object

The net force on the object

The normal force on the object

When objects are in contact with each other and moving together what is the acceleration of each object?

The ratio of the accelerations is equal to the ratio of the masses.

The ratio of the accelerations is equal to the ratio of their volumes

The acceleration depends on the area of contact.

They have the same acceleration

They have the same acceleration

When analyzing an interaction involving three interacting objects how many free body diagrams need to be drawn?

3 - one for each object

The number of diagrams depends on how the objects are arranged.

0 - can't draw free body diagrams for interacting objects

1 - all objects together

3 - one for each object

If the speed of a moving object is not changing, then

There are no forces on the object

The net force is zero

The net force is in the direction of the motion

The net force is in the direction opposite the motion.

The net force is zero

When an object's speed is decreasing

The net force and the acceleration are in the same direction of the motion

The net force and the acceleration are opposite the motion

The net force is opposite the motion, and the acceleration is in the direction of the motion

The net force is in the direction of the motion, and the acceleration is opposite the motion

The net force and the acceleration are opposite the motion

Which of Newton's laws are important for analyzing interacting objects?

Only the 3rd law (law of force pairs)

None of Newton's laws help in this situation.

Only the 2nd law (law of motion)

The 2nd and 3rdlaws

The 2nd and 3rdlaws

What approximations are made when dealing with pulleys and ropes in chapter 5?

All of these

There are no simplifications

The pulley is frictionless

The pulley is massless

The string is massless

All of these

When two objects are connected by a string how are the tension forces on each object related?

The tension forces on each object are the same

The relationship between the tension forces depends on the type of string.

The ratio of the tension forces is equal to the ratio of the masses

The ratio of the tension forces is equal to the ratio of the surface areas

The tension forces on each object are the same

How does a massless, frictionless pulley change the tension in a string?

The pulley changes nothing.

Changes the direction and magnitude of the tension

Changes the direction of the tension

Changes the magnitude of the tension

Changes the direction of the tension

How does banking a curve on the highway allow cars to drive at a higher speed in the curve?

The normal force provides some centripetal acceleration

The frictional force is increased.

The normal force provides some centrifugal acceleration

the normal force is increased.

The normal force provides some centripetal acceleration

At what point on a roller coaster loop is your apparent weight the greatest

Half way up while moving up

Top

Half way up while moving down

Bottom

Bottom

The time for an object to complete one revolution is caller

Frequency

Period

rpm

Angular velocity

Period

A car rounding a corner at a constant speed has

Acceleration directed forward

Acceleration directed backward

Acceleration toward the center of the curve

Zero acceleration

Acceleration toward the center of the curve

What is the force, F, needed to keep an object with mass m in a circular path with radius r at a speed v?

F = mv2/r

F = r/mv

F = mrv2

F = v2/mr

F = mv2/r

The centrifugal force

Is not a real force

Keeps planets in orbit around a star

Pulls on object into a turn

Pushes objects out of a turn

Is not a real force

How are period (T) and frequency (f) in circular motion related?

T = 1/f

T = f

T = 1/f2

T = f2

T = 1/f

The critical speed for traveling around a vertical loop

Is the slowest possible speed that can still complete the loop

Is the speed at which the normal force is zero at the top

Depends on the radius of the loop

All of the above

All of the above

Your maximum walking speed is determined by

The flexibility in your hips

The mass of your leg

The rate of arm motion

The length of your leg

The length of your leg

The maximum safe speed to turn a corner depends on

The kinetic friction between the tires and the road

The static friction between the tires and the road

The mass of the car

The length of the car

The static friction between the tires and the road

Newton's Law of Gravity says the gravitational force between two objects is related to the distance, r, between them as

r2

r

1/r

1/r2

1/r2

The speed of a satellite in a circular orbit around a star does not depend on

The mass of the star

The mass of the satellite

The speed depends on all of these

The distance between the star and the satellite

The mass of the satellite

As the distance between 2 objects increases, what happens to the force of gravity between them?

The force is constant

The change in the force depends on the ratio of the masses.

The force increases

The force decreases

The force decreases

Two planets have the same mass, but planet X has twice the radius of planet Z. How does the acceleration due to gravity compare between the two?

Acceleration due to gravity is larger on X

Acceleration due to gravity is larger on Z

Acceleration due to gravity is the same on both

This is not in this chapter.

Acceleration due to gravity is larger on Z

The acceleration due to gravity near the surface of the moon depends on

The mass of the moon

Nothing. The acceleration due to gravity is the same everywhere.

The radius of the moon

The mass and radius of the moon

The mass and radius of the moon

A satellite is in a circular orbit around the Earth. What mass(es) does the orbital speed depend on?

Mass of the Earth only

The speed does not depend on mass.

Mass of the Earth and the satellite

Mass of the satellite only

Mass of the Earth only

The feeling of weightless near the Earth means

None of these

There is no gravity

The weight is zero

The object is in free fall

The object is in free fall

Which of these is in free fall around the Earth?

A GPS satellite

The moon

All of these

The international space station

All of these

The period of a satellite orbiting a planet does not depend on

The period depends on none of these.

The distance between the planet and the satellite

The mass of the planet

The mass of the satellite

The mass of the satellite

An object in orbit around the Earth

Has no forces acting on it

Must have a force pushing it forward

Is in free fall

Must be very far from the Earth (outside the moon's orbit)

Is in free fall

The unit for angular position used in this chapter is

Degrees

Arc sec

Meters/second

Radians

Radians

Tangential acceleration is equal to

α

acp

α*r

α/acp

α*r

If the center of gravity of an object is below its pivot point, the object will

Experience no torque

Experience counterclockwise torque due to gravity

Experience clockwise torque due to gravity

Rotate continuously

Experience no torque

Which situation creates the largest torque for the same amount of force

Short r with force parallel to radial line

Short r with force perpendicular to radial line

Long r with force parallel to radial line

If force is the same torque is the same

Long r with force perpendicular to radial line

Long r with force perpendicular to radial line

The center of gravity of an extended object

Is not in this chapter

Can be calculated from the center of gravity of individual pieces of the object

Is the center of gravity of the largest piece

Is the center of gravity of the smallest piece

Can be calculated from the center of gravity of individual pieces of the object

An object moving in uniform circular motion has

Increasing frequency

Constant non-zero angular acceleration

Constant angular velocity

Constant angular position

Constant angular velocity

Which is true for a rotating object?

acp = α always

α>acp always

acp>0 even when α=0

α>0 even when acp=0

acp>0 even when α=0

Torque depends on

Angle of the force

All of these.

Magnitude of the force applied

Distance, r, of applied force from pivot point

All of these

Angular velocity is positive for

clockwise rotation

depends on the situation

angular velocity has no sign

counterclockwise rotation

Counterclockwise rotation

Every point on a rotating rigid body has the same

Linear velocity

Acceleration

Angular velocity

Radial position

Angular velocity

The moment of inertia of an extended object depends on

All of these

Mass of the object

The shape of the object

Location of the rotation axis

All of these

What is the rotational analog to mass?

α

I

τ

F*m

I

An object is connected to a string which goes over a pulley which has mass and a radius R. How is the speed of the object, v, related to the rotation of the pulley?

There is no relation.

v = ωR

v = R/ω

v = ω/R

v = ωR

How are angular acceleration, α, and torque, τ, related for a single particle with mass m?

α = τ/(mr2)

α = rFm

α = τ/m

α = τmr2

α = τ/(mr^2)

Newton's 2nd law for rotation says αis proportional to

F+τ

Mass

τnet

Fnet

τnet

Rolling motion

Depends on a momentarily stationary pivot point

All of these are true

Is a combination of linear and rotational motion

Has a different speed for each point on the object

All of these are true

A car is moving at 10 m/s. What is the speed of the point on the tire which is in contact with the road?

0 m/s

5 m/s

10 m/s

20 m/s

0 m/s

What has the larger moment of inertia, a cylindrical disk or a cylindrical hoop? They have the same mass and radius.

Depends on what they are made of

They have the same moment of inertia

Disk

Hoop

Hoop

How does including the mass and radius of a pulley change the time for a bucket attached to a string going around a pulley to fall?

Depends on the mass of the pulley

Fall time is constant

Decreases the time for the bucket to fall.

Increases the time for the bucket to fall

Increases the time for the bucket to fall

An object is connected to a string which goes over a pulley which has mass and a radius R. How is the acceleration of the object, a, related to the rotation of the pulley?

a = α/R

There is no relation.

a = R/α

a = αR

a = αR