chapter 12 Flashcards
The graph shows the angular position of a bicycle wheel spoke as a function of time. Take positive values of theta to represent counterclockwise angular measurements. From the graph, what can you determine about the wheel’s angular velocity, vector omega?
The angular velocity is zero.
How do you measure 1 radian?
One radian is the angle at which the arc s has the same length as the radius r.
When an object is rotating, how is the tangential acceleration of a point on its outer edge (at a distance r from the axis of rotation) related to its angular acceleration?
a sub t equals r times alpha
A brother and sister are riding on a merry-go-round at the park. The brother rides on the outer edge of the merry-go-round and the sister rides closer to the center. While the merry-go-round rotates with an increasing angular velocity, who has the greatest tangential acceleration?
The brother has the greatest tangential acceleration.
A wheel is rotating counterclockwise, which we will define as the positive direction, at an angular velocity of 2 rad/s. If the wheel then experiences a counterclockwise angular acceleration of 1 rad/s2, what is the wheel’s angular velocity 3 seconds later?
5 rad/s counterclockwise
A bicycle wheel rotates counterclockwise at a constant rate. You can use one of the wheel’s spokes to measure the wheel’s angular displacement, Delta theta. How is this angular displacement related to the radius of the wheel, r, and the arc length, s, along the circumference of the wheel?
Delta theta equals s over r
A Blu-ray disc rotates counterclockwise and speeds up at a constant rate. How does the angular acceleration of point P compare to the angular acceleration of point Q?
The angular acceleration of point P is equal to the angular acceleration of point Q.
A bicycle wheel rotates counterclockwise at a constant rate. You can use one of the wheel’s spokes to measure the wheel’s angular displacement. What are the appropriate units for this measurement?
radians (rad)
A brother and sister are riding on a merry-go-round at the park. The brother rides on the outer edge of the merry-go-round and the sister rides closer to the center. While the merry-go-round rotates with a constant angular velocity, who has the greatest centripetal (radial) acceleration?
The brother has the greatest centripetal (radial) acceleration.
A Blu-ray disc rotates counterclockwise at a constant rate, as shown in the figure. How does the angular velocity of point P compare to the angular velocity of point Q?
The angular velocity of point P is equal to the angular velocity of point Q
The graph shows the angular velocity of a bicycle wheel as a function of time. Take positive values of omega to represent counterclockwise measurements. From the graph, what can you determine about the wheel’s angular acceleration, vector alpha?
The angular acceleration is constant and counterclockwise.
A wheel is rotating counterclockwise, which we will define as the positive direction, at an angular velocity of 2 rad/s. If the wheel then experiences a clockwise angular acceleration of 1 rad/s2, what is the wheel’s angular velocity 3 seconds later?
1 rad/s clockwise
A Blu-ray disc rotates counterclockwise and speeds up at a constant rate. How does the tangential acceleration of point P compare to the tangential acceleration of point Q?
The tangential acceleration of point P is less than the tangential acceleration of point Q.
A bicycle wheel rotates counterclockwise at a constant rate. What are the appropriate units for a measurement of the wheel’s angular velocity?
rad/s
A wheel with a 3-m radius rotates with constant angular velocityomega= 2 rad/s. During 1 second, what is the wheel’s angular displacement?
2 rad