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WorksheetsUnit 7: Rotational Kinematics
Total questions: 46
Worksheet time: 37mins
A fan spins with a constant angular speed of 500 radians/second. How long will it take to cover an angle of 2π radians (one revolution)?
0.013 s
0.002 s
76.9 s
6.28 s
A disk initially rotating counterclockwise (CCW) at a certain constant angular speed is suddenly being pulled on by two strings T1 and T2, where T2 > T1. What is going to happen next?
The disk will continued rotating CCW at the constant angular speed.
The disk will continued rotating CCW but it will speed up
The disk will slow down and start rotating CW
The disk will eventually stop rotating
Two wheels are fixed to each other and are free to rotate about a frictionless axis through their concentric centers. Four forces are exerted tangentially to the wheels. As a result of the net torque on the wheels, the wheels will rotate-
clockwise
counterclockwise
It is the state of a rigid body where a solid object is not moving because its influences are balanced
Average Linear Velocity
Rotational Kinematics
Static Equilibrium
Torque
The diagram above shows a top view of a child of mass M on a circular platform of mass 5M that is rotating counterclockwise. Assume the platform rotates without friction. Which of the following describes an action by the child that will result in an increase in the total angular momentum of the child-platform system?
The child moves toward the center of the platform.
The child moves away from the center of the platform.
The child moves along a circle concentric with the platform (dashed line shown) opposite the direction of the platform’s rotation.
None of the actions described will change the total angular momentum of the child-platform system.
A diver in a swimming pool bends his head before diving. It
Increases his linear velocity
Decreases his angular velocity
Increases his moment of inertia
Decreases his moment of inertia
ω
v
θ
x
α
a
ωf=ωo+αt
Vf=Vo+at
(a) is how fast an object is rotating at a specific moment in time.
α
angular acceleration
τ
torque
ω
angular velocity
θ
angular displacement
ι
moment of inertia
(a) α tells how much an object’s angular speed changes in one second. It is measured in rad/s per second.
(a) θ indicates the angle through which an object has rotated. It is measured in radians.
(a) changes an object’s rotational speed, while (b) changes an object’s direction of motion.
(a) ω is angular displacement divided by the time interval over which that angular displacement occurred. It is measured in rad/s.
Rotational inertia I represents an object’s resistance to angular acceleration.
Like mass, it is a (a) quantity
A constant net torque is applied to a system. Which system would experience the largest angular acceleration?
A very massive system with a small rotational inertia
A low mass system with a small rotational inertia
A low mass system with a large rotational inertia.
Equal torques produce the same angular acceleration for every system.
Net torque
Causes angular acceleration
Net force
Causes linear acceleration
Net torque is zero
Constant angular velocity
Net force is zero
Constant velocity or at rest
What angular variable is comparable to the tangential variable of acceleration?
ω
Θ
α
π
What angular variable is comparable to the tangential variable of velocity?
ω
Θ
α
π
The SI units for α are
rad
rad/s
rad/s2
seconds
The SI units for Θ are
rad
rad/s
rad/s2
seconds
The SI units for ω are
rad
rad/s
rad/s2
seconds
Is there an example of when a car can experience both centripetal and angular acceleration?
No; both accelerations cannot act at the same time
Yes; when the car is changing its speed around a curve
No; the car only experiences centripetal acceleration around a curve
Yes; when the car is moving in a straight line
Why does mud fling off the tires if the tires are rotating fast?
The mud is to heavy on the tires and flings off
The centripetal force isn't enough to hold the mud and it flings off
Gravity pulls the mud off when the tires rotate to fast
The angular acceleration in circular motion
Is equal in magnitude to the tangential acceleration divided by the radius
Increases the angular velocity in the same direction
Has units of rad/s2
All of the above
If the centripetal force on a particle in uniform circular motion is increased,
The tangential speed remains constant
The tangential speed will decrease
The radius of the circular path will increase
The tangential speed will increase and/or the radius will decrease
In uniform circular motion, there is a
Constant velocity
Constant angular velocity
Zero acceleration
Net tangential acceleration
What does the term "tangential" mean?
Moving forward
Moving in a circle
Moving in a straight line
Moving around
A top completes 200 revolutions around. How would you convert that radians?
Divide by 2π
Multiply by 2π
Divide by π
Multiply by π
When driving your car around a curve, why do you lean the opposite the direction of the turn?
Gravity
Inertia
Weight
Centripetal Force
Why do the clothes in a washing machine fling outward along the edge of the drum?
Centripetal force isn't enough to pull them into the center of the drum, so the clothes are flung outward toward the edge of the drum
Centripetal force is enough to pull them into the center of the drum, pushing them outward to the edge of the drum
Gravity pulls the clothes to the outside of the drum
Centripetal force can also be what other forces? Select two.
Weight
Friction
Tension
Air Resistance
What does the term "centripetal" mean?
Center fleeing
Center seeking
Rotation
Circular
The "centrifugal force" describes what actual physics phenomena?
Mass
Weight
Rotational motion
Inertia
Are astronauts really weightless?
Yes; they have no weight in space
Yes; they are in space where there is no gravity
No; they are in a constant state of free fall rotating around the Earth
No; the moon pulls on them with its gravity making them appear weightless
There are two bugs, a ladybug and a beetle, sitting on a rotating turntable which has an angular velocity ω . The ladybug is at the outer edge of the turntable and the beetle is closer to the center of the axis of rotation. Which of the following statements is true?
The ladybug and the beetle have the same angular velocity. The ladybug has a smaller linear velocity and the beetle has a greater linear velocity.
The ladybug and the beetle have the same angular velocity. The ladybug has a greater linear velocity and the beetle has a smaller linear velocity.
The ladybug and the beetle have different angular velocities. They both have the same linear velocities.
The ladybug and the beetle have different angular velocities. You cannot determine the linear velocities of either bug because they are rotating.
