AP PHYSICS UNIT 6 - ACELLUS

Translational motion can be best described as... A. a combination of both linear and circular motion B. motion in a straight line C. circular motion

B. Motion in a straight line

How would increasing the mass of an object affect its angular momentum? A. angular momentum would decrease B. angular momentum would increase C. angular momentum would remain constant

B. angular momentum would increase

An object is undergoing translational motion with a speed of "v" at the center. If the object is 2 m wide, what is the velocity on the edge of the object? A. 2v B. 1/2 V C. V

C. V

A moment arm of zero would be produced if the applied force... A. was directed perpendicular to the axis of rotation B. was directed at a 45 degree angle to the axis of rotation C. was directed at the axis of rotation

C. Was directed at axis of rotation

Rotational work can only be done 4 if... A. the lever arm is changed B. the object's moment of inertia changes C. a net torque is applied

C. a net torque is applied

Which of the following is NOT a condition for static equilibrium? A. all angular velocities are zero B. all linear velocities are zero C. all torques are zero

C. all torques are zero

A washing machine contains a load of blankets when it begins to spin. The heavy blankets could... A. alter the mass distribution but this would not change the moment of inertia B. change the axis of rotation C. alter the mass distribution and change the moment of inertia

C. alter the mass distribution and change the moment of inertia

When measuring the velocity of the center of mass, what are the preferred units? A. radians/second B. degrees/second C. meters/second

C. meters/second

When calculating rotational work, the angle of movement should be measured in... A. degrees B. revolutions C. radians

C. radians

Two different forces produce the same amount of torque. This means...

There may be no similarities

A force of 500 N is applied to an object. Which angle would produce the greatest torque? A. 90° B. 10° C. 45°

90°

In which type of motion do all the particles have the same instantaneous velocity?

Translational

Multiplying the angular velocity by the radius will provide the...

Velocity of the center of mass

Which formula could NOT be used to determine the velocity of the center of mass? A. s/t C. rw B. re D. re/t

r0

A boat is floating on a lake when a boater stands up and walks from one end of the boat to the other. This would cause a change in... A none of the above C the net force on the boat B the boar's momentum D the boat's acceleration

A. None of the above

When measuring angular velocity, one should use units of... A. radians/second B. degrees/second C. meters/second

A. Radians/second

The lever arm is best thought of as... A. the resistance to change in rotational motion B. the direction of the applied force C. the distance between the axis of rotation and the applied force

C. the distance between the axis of rotation and the applied force

When calculating the moment of inertia, which of the following pieces of information is NOT necessary? A. the axis on which the object rotates B. the mass distribution of the object C. the gravitational force acting on the object

C. the gravitational force acting on the object

When an object is in mechanical equilibrium, ... A. the object must be rotating at a constant rate B. all torques must pass through the axis of rotation C. the object must be at rest

C. the object must be at rest

An object is in rotational equilibrium if... A. non-concurrent forces act on it B. a net torque acts on it C. the sum of all torques acting on it is zero

C. the sum of all torques acting on it is zero

Which of the following MUST be met to establish mechanical equilibrium? A. all angular velocities must be constant B. all linear velocities must be constant C. the sum of all torques must be zero

C. the sum of all torques must be zero

A wheel requires 4.0 seconds to spin. through an arc length of 0.25 meters. What is the velocity of the center of mass of the wheel?

0.0625

A 50 kg person is standing at the back of a 2.5 meter long rowboat. If the person walks to the opposite end of the rowboat, by how many meters will the center of mass of the boat change?

0

A person uses an electric drill to remove a screw. The drill applies a force of 250 N at a 90° angle. The radius of the drill is 0.5 cm. What is the length of the moment arm?

.005

A rotating object has an angular velocity of 4.5 rad s and a center of mass velocity of 1.2 * m/s . What is the radius of the object?

.267

An object has a radial velocity of 2.5 rad s . If it has a radius of 0.20 m, what is its center of mass velocity?

.5

An object has an angular velocity of 3.5 rad s and maintains it for 4.5 seconds. Through how many total radians will it rotate?

15.75

A 125 N force is applied to loosen a bolt. The force is applied at a 40 deg angle to the bolt, and the wrench is 20 cm long. Determine the amount of torque applied.

16.1

Determine the center of mass for the system below. The distance measurements are in meters. 2.0 kg 3.0 kg

2.2

A rolling object subtends an angle of 4pi radians. If the radius is 0.20 m, what is the arc length?

2.51

A brace is used to support a hanging sign. The brace makes an angle of 25° and has a tension of 50 N. What is the total force on the brace in the Y-direction?

21

A car is traveling at 25m / s . The center of the tire is also moving at 25m / s What is the linear velocity of a spot at the top of the tire?

50

A net torque is applied to an object in a counterclockwise direction. Which sign would be given to the torque? A. + B. -

A. +

An arc length equal to the radius of a circle is called... A. 1 radian B. 360 degrees C. 180 degrees

A. 1 radian

A picture frame is hanging on a wall. To maintain static equilibrium, ... A. all forces must be concurrent B. a net force must act C. a net torque must act

A. All forces must be concurrent

What are concurrent forces? A. forces that act through the same line of action B. forces that are parallel to each other C. forces that cancel each other out

A. Forces that act through the same line of action

An applied force could produce NO change in rotation if... A. it was applied the axis of rotation B. it was applied at a 90 degree angle to the axis of rotation C. it was applied directly at the surface of the object

A. It was applied to the axis of rotation

Angular momentum is conserved. Which variable would be used to represent angular momentum? A. L B. M C. A

A. L

Which of the following variables is NOT needed to determine rotational kinetic energy? A. mass B. moment of inertia C. angular velocity

A. Mass

When an object is in stable equilibrium a small displacement will... A. result in a restoring force that returns the object to its equilibrium position B. result in a torque that rotates the object further from its equilibrium position C. not affect the object

A. Result in a restoring force that returns the object to its equilibrium position

An object is rotationally at rest. This is an example of... A. rotational equilibirum B. translational equilibrium C. mechanical equilibrium

A. Rotational equilibrium

A rolling object covers an arc length of s in time t. If its velocity were to double, what arc length would be covered in the same amount of time? A. twice the arc length B. the same arc length C. half the arc length

A. Twice the arc length

Which of the following would NOT be an example of an object in static equilibrium? A. a motor spins at a constant velocity B. a picture frame hanging on a wall C. a ladder at rest against a wall

A. a motor spins at constant velocity

In which situation would the concept of center of mass best apply? A. a system composed of multiple particles B. a system composed of a single particle C. a system composed of no particles

A. a system conposed of multiple particles

Rotational equilibrium occurs when... A. all torques acting on the object are balanced B. the object is not rotating C. no torques act on the object

A. all torqued acting on the object are balanced

In the rotational version of Newton's Second Law, the rotational equivalent to mass, is... A. moment of inertia B. torque C. impulse

A. moment of inertia

The center of mass and center of gravity will coincide if... A. the acceleration due to gravity is constant B. the object is at rest C. the object is not experiencing an unbalanced force

A. the acceleration due to gravity is constant

A good definition of center of gravity is... A. the location in which all the weight of an object acts B. the center of the object C. the location at which the normal force acts

A. the location in which all the weight of an object acts

Which set of criteria MUST be met if an object is in static equilibrium? A. The object must have no linear or angular velocity B. The object must maintain a constant linear velocity C. The object must maintain a constant angular velocity

A. the object must have no linear or angular velocity

The moment arm can be calculated using which of the following formulas? A. R*theta B. R * sin theta C. R * cos theta

B R * sin0

Static equilibrium can be described as... A. a rigid body maintaining constant velocity B. a rigid body at rest C. a rigid body experiencing balanced torques

B. A rigid body at rest

Translational equilibrium occurs when... A. all torques are balanced B. all forces are balanced C. the object is stationary

B. All forces are balanced

Which of the following would NOT affect the force needed to open a door? A. making a wider door B. changing the door height C. changing the lever arm D. changing the door mass

B. Changing the door height

A person slams a door. How would increasing the width of the door affect its acceleration? Assume that all other variables are kept constant. A. it would increase B. it would decrease C. it would be unaffected

B. It would decrease

An extended line on which the applied force acts is known as the... A. lever arm B. line of action C. moment arm

B. Line of action

When all conditions for both rotational and translational equilibrium are met, the object is in... A. balanced equilibrium B. mechanical equilibrium C. concurrent equilibrium

B. Mechanical equilibrium

All forces acting on an object are balanced. Does this mean the object is in mechanical equilibrium? A. Yes. If all forces are balanced the conditions for mechanical equilibrium are met. B. No. The object can be in motion if balanced forces act on it. C. Yes. Balanced forces will not produce an acceleration

B. No. The object can be in motion if balanced forces act on it

An object undergoes a displacement. This displacement will cause the center of gravity to... A. remain in the same location B. raise and increase the potential energy C. lower and decrease the potential energy

B. Raise and increase the potential energy

The variable c_{m}' is used to designate... A. the combined mass of the system B. the center of mass C. the momentum of the system

B. The center of mass

A small mobile is hanging in a child's bedroom. The mobile will be in rotational equilibrium if... A. a net torque acts on it B. the normal force acts through the axis of rotation C. the normal force acts parallel to the axis of rotation

B. The normal force acts through the axis of rotation

Two different spinning disks both have the same angular momentum, but one spins twice as fast. This would only be possible if... A. the slower disk had half the moment of inertia B. the slower disk had twice the mass C. the slower disk had twice the length of the lever arm

B. The slower disk had twice the mass

A picture frame is hanging on a wall in static equilibrium. To maintain static equilibrium, ... A. the tension and weight must be on separate moment arms B. the tension and weight must pass through the same point C. the tension and weight must act at 90 degree angles

B. The tension and weight must pass through the same point

In the rotational version of Newton's Second Law, the equivalent to force is... A. moment of inertia B. torque C. impulse

B. Torque

A rolling object covers an arc length of s in time t. If its velocity were to double, what arc length would be covered in the same amount of time? A. the same arc length B. twice the arc length C. half the arc length

B. Twice the arc length

The resultant of concurrent forces is always... A. greater than any one of the individual forces B. zero C. the sum of the magnitudes of each individual force

B. Zero

A force is applied to an object and the object begins to rotate. This rotation would be... A. a translational acceleration B. a rotational acceleration C. a linear acceleration

B. a rotational acceleration

When calculating center of mass, "X" refers to... A. the combined mass of all objects B. the distance between the object and a reference point C. the mass of each object

B. the distance between the object and a reference point

A car is moving at a speed of "v". What is the instantaneous velocity of the point of the tire making contact with the road? A. v B. 2v C. O

C. 0/zero

A tire is rolling with a speed at the center of the tire of "v". What is the speed of the tire at the top? A. v B. O C. 2v

C. 2v

Net work can be described as... A. a change in net torque B. a change in rotational motion C. a change in rotational kinetic energy

C. A change in rotational kinetic energy

Rolling motion can be thought of as... A. motion in which each particle has the same instantaneous angular velocity B. the difference between translational and rolling motion C. a combination of translational and rotational motion

C. A combination of translational and rotational motion

An object is moving at a constant velocity of 20 * m/s Which statement about this situation is NOT correct? A. Concurrent forces are acting on the object B. The object is in translational equilibrium C. A torque can be acting on the object

C. A torque can be acting on the object

The vibrate feature on a cell phone is caused by a small spinning disk with its axis of rotation slightly off center. Changing this axis of rotation would... A. not affect the translational acceleration of the disk B. not affect the overall torque C. affect the moment of inertia of the disk

C. Affect the moment of inertia of the disk

Stated appropriately, Newton's second law states that... A. application of a net force will cause an equal net force in an opposite direction B. application of a balanced force will cause an acceleration C. application of a net force will cause an acceleration of the center of mass

C. Application of a net force will cause an acceleration of the center of mass

Two children are on a merry go round with a 4.0 meter radius. One child is on the edge and the other halfway to the center. Which statement about this is correct? A. The child on the edge has twice the angular velocity of the child in the middle B. Both childreg have the same linear velocity C. Both children have the same angular velocity

C. Both have the same angular velocity

The rate of change in rotational motion depends upon all of the following EXCEPT for the... A. magnitude of applied force B. distance between line of action and axis of rotation C. duration of the applied force

C. Duration of the applied for w

An object with a constant angular velocity is said to be... A. in translational equilibrium B. in rotational intertia C. in rotational equilibrium

C. In rotational equilibrium

A small displacement affects an object. Afterwards, the center of gravity lies within the original base of support. This means the object is... A. in unstable equilibrium B. in mechanical equilibrium C. in stable equilibrium

C. In stable equilibrium

A wrench is used to loosen a rusted bolt. Increasing the length of the wrench would... A have no affect on the applied torque B. increase the angle of the applied torque C. increase the length of the lever arm

C. Increase the length of the lever arm

Which statement about the center of gravity is false? A. It can commonly be calculated using the formula for center of mass B. It rises when a small displacement occurs C. It is affected by the shape of an object

C. It is affected by the shape of an object

The radial velocity of an object doubles. How would this alter the object's kinetic energy? A. it would double as well B. it would triple C. it would be four times as much

C. It would be four times as much

Which of the following variables is NOT needed to calculate rotational work? A. applied torque B. angle of movement C. moment of inertia

C. Moment of inertia

The variable "I" is used to refer to... A. torque B. translational inertia C. moment of inertia

C. Moment of interia

What is NOT required for an object to be in equilibrium? A. all torques are in balance B. all forces are in balance C. object to be stationary

C. Object to be stationary

Which of the following variables would NOT be needed to calculate angular momentum? A. mass B. lever arm C. tension D. angular velocity

C. Tension

A torque of -75 N is applied to an object. What would the result of this torque be? A. there's not enough information to answer the question B. the object would spin in a counterclockwise direction C. the object would spin in a clockwise direction

C. The object would spin in a clockwise direction

A ball is attached to a string and swung in a circle. How should the tension in the string be handled as part of the calculation for angular momentum? A. The tension force should be divided by 9.8 to obtain the mass (w = mg) B. The tension force should be multiplied by the mass of the object being swung C. The tension force should be ignored as it passes through the axis of rotation

C. The tension force should be ignored as it passes through the axis of rotation

The reel of a fishing line contains 5.0 cm of wound line. Assuming a large fish is caught, and begins to unwind the line, how will the amount of torque change? A. torque will stay the same B. torque will increase C. torque will decrease

C. Torque will decrease

When calculating the acceleration of a slammed door, which variable would NOT be needed? A. mass of the door B. radius of the door D. the height of the door C. the lever arm

D. the height of the door

Torque can be defined as the product of... A. force distance B. force lever arm C. force sine

Force • lever arm

When measuring arc length, what units should be used? A. radians B. degrees C. meters

Meters

When measuring the radius of circle, what units should be used? a A. radians B. meters C. degrees

Meters

When measuring torque, the units should be... A. joules B. newtons C. meters newtons

Meters • newtons

The straight line distance between the axis of rotation and the force line of action is abbreviated... A. R B. 0 C. ri

R

When measuring the angle of rotation, what are the preferred units?

Radians

In which type of motion would all particles have the same instantaneous angular velocity?

Rotational

A tire begins to roll. The distance the tire rolls in a set amount of time is called... A. 0 B. S C. r

S

How is angular velocity abbreviated?

W