Physics Chapter 8
A circular hula hoop rolls upright without slipping on a flat horizontal surface. Which one of the following statements is necessarily true?
Every point on the rim of the wheel has a different velocity
A rigid body rotates about a fixed axis was a constant angular acceleration. Which one of the following statements is true concerning the tangential acceleration of any point on the body?
The tangential acceleration depends on the change in the angular velocity
A wheel with a 0.10-m radius is rotating at 35 rev/s. It then slows uniformly to 15 rev/s over a 3.0-s interval. What is the angular acceleration of a point on the wheel?
-6.7 rev/s^2
The original ferris wheel had a radius of 38m and completed a full revolution (2p radians) every two minutes when operating at its maximum speed. If the wheel were uniformly slowed from its maximum speed to a stop in 35 seconds, what would be the magnitude of the tangential acceleration at the outher rim of the wheel during its deceleration?
0.057 m/s^2
What is the angular speed in rad/s of the second hand of a watch?
0.10 rad/s
On an amusement park ride, passengers are seated in a horizontal circle of radius 7.5m. The seats begin from rest and are uniformly accelerated for 21 seconds to a maximum rotational speed of 1.4 rad/s What is the tangential acceleration of the passengers during the first 21 s of the ride?
0.50 m/s^2
A wheel of radius 0.5m rotates with a constant angular speed about an axis perpendicular to its center. A point on the wheel that is 0.2 m from the center has a tangential speed of 2 m/s Determine the tangential acceleration of the point that is 0.2m from the center.
zero m/s^2
A grindstone of radius 4.0m is initially spinning with an angular speed of 8.0 rad/s. The angular speed is then increased to 12 rad/s over the next 4.0 seconds. Assume that the angular acceleration is constant. What is the magnitude of the angular acceleration of the grindstone?
1.0 rad/s^2
Joe is painting the floor of his basement using a paint roller. The roller has a mass of 2.4kg and a radius of 3.8 cm. In rolling the roller across the floor, joe applied a force F= 16 N directed at an angle of 35 degrees as shown. Ignoring the mass of the roller handle, what is the magnitude of the angular acceleration of the roller?
1.0 x10^2 rad/s^2
Two motorcycles are riding around a circular track at the same angular velocity. One motorcycle is at a radius of 15m; and the second is at a radius of 18m. What is the ratio of their linear speeds, v2v1?
1.2
A grindstone of radius 4.0m is initially spinning with an angular speed of 8.0 rad/s. The angular speed is then increased to 12 rad/s over the next 4.0 seconds. Assume that the angular acceleration is constant. What is the average angular speed of the grindstone?
10 rad/s
A wheel of radius 0.5m rotates with a constant angular speed about an axis perpendicular to its center. A point on the wheel that is 0.2 m from the center has a tangential speed of 2 m/s Determine the angular speed of the wheel
10 rad/s
A 2.0-kg solid diskc rolls without slipping on a horizontal surface so that its center proceeds to the right with speed 5.0m/s What is the instantaneous speed of point A with respect to the ground?
10.0 m/s
A long thing rod of length 2L rotates with a constant angular acceleration of 8.0 rad/s^2 about an axis that is perpendicular to the rod and passes through its center What is the ratio of the centripetal acceleration of a point on the end of the rod to that of a point a distance L/2 from the end of the rod?
2:1
A sculptor is sharpening a chisel on a grindstone of radius 1.0m that is spinning with a constant angular speed of 2.0 rad/s What is the magnitude of the centripital acceleration of a point on the rime of the grindstone?
4.0 m/s^2
A bicycle wheel of radius 0.70m is rotating at an angular speed of 6.3 rad/s as it rools on a horizontal surface without slipping. What is the linear speed of the wheel?
4.4 m/s
a ball attaches to a string starts at rest and undergoes a constant angular acceleration as it travels in a horizontal circle of radius 0.30m. After 0.65 s, the angular speed of the ball is 9.7 rad/s. What is the tangential acceleration of the ball?
4.5 m/s^2
What is the tangential speed of a lug nut on a wheel of a car if the lug nut is located 0.114 m from the axis of rotation; and the wheel is rotating at 6.53 rev/sec?
4.68 m/s
A bicycle travels 141 m along a circular track of radius 30 m. What is the angular displacement in radians of the bicycle from its starting position?
4.7 radians
A grindstone of radius 4.0m is initially spinning with an angular speed of 8.0 rad/s. The angular speed is then increased to 12 rad/s over the next 4.0 seconds. Assume that the angular acceleration is constant. Through how many revolutions does the grindstone turn during the 4.0 second interval?
40
An airplane engine starts from rest; and 2 seconds later, it is roating with an angular speed of 420 rev/min. If the angular acceleration is constant, how many revolutions does the properller undergo during this time?
7
A 2.0-kg solid diskc rolls without slipping on a horizontal surface so that its center proceeds to the right with speed 5.0m/s What is the instantaneous speed of point B with respect to the ground?
7.1 m/s
A bicycle with wheels of radius 0.4 m travels on a level road at a speed of 8 m/s. What is the angular speed of the wheels?
20 rad/s
A 2.0-kg solid diskc rolls without slipping on a horizontal surface so that its center proceeds to the right with speed 5.0m/s What is the direction of the disks angular velocity?
into the paper (away from you)
Which one of the following statements concerning a wheel undergoing rolling motion is true?
there is no slipping at the point where the wheel touches the surface on which it is rolling
A top is spinning counterclockwise as shown in the figure. It is also moving to the right with a linear speed v. What is the direction of the angular velocity?
upward
Which equation is valid only when the angular measure is expressed in radians?
w = (Vr)/r
A 2.0-kg solid diskc rolls without slipping on a horizontal surface so that its center proceeds to the right with speed 5.0m/s What is the instantaneous speed of the point of the disk that makes contact with the surface?
zero m/s
A sculptor is sharpening a chisel on a grindstone of radius 1.0m that is spinning with a constant angular speed of 2.0 rad/s What is the magnitude of the tangential acceleration of a point on the rim of the wheel?
zero m/s^2
During the spin-dry cycle of a washing machine, the motor slows from 90 rad/s to 30 rad/s while the turning the drum through an angle of 180 radians. What is the magnitude of the angular acceleration of the motor?
20 rad/s^2
A bicycle has tired of radius 0.35 meters. If the bicycle is traveling at a constant speed of 7.8 m/s, at approximately what angular speed are the tires rotating?
214 rev/min
A bicycle wheel of radius 0.70m is rolling without slipping on a horizontal surface with an angular speed of 2.0 rev/s when the cyclist begins to uniformly apply the breaks. The bicycle stops in 5.0s How far did the bicycle travel during the 5.0 seconds of braking?
22 m
A 1.0m roulette wheel reaches a maximum angular speed of 18 rad/s before it begins decelerating. After reaching this maximum angualr speed, it turns through 35 revolutions (220 rad) before it stops. How long did it take the wheel to stop after reaching its maximum angular speed?
24 s
A long thing rod of length 2L rotates with a constant angular acceleration of 8.0 rad/s^2 about an axis that is perpendicular to the rod and passes through its center What is the ratio of the tangential acceleration of a point on the end of the rod to that of a point a distance L/2 from the end of the rod?
2:1
A long thing rod of length 2L rotates with a constant angular acceleration of 8.0 rad/s^2 about an axis that is perpendicular to the rod and passes through its center What is the ratio of the tangential speed (at any instant) of a point on the end of the rod to that of a point a distance L/2 from the end of the rod?
2:1
A wheel of radius 0.5m rotates with a constant angular speed about an axis perpendicular to its center. A point on the wheel that is 0.2 m from the center has a tangential speed of 2 m/s Determine the tangential speed of point 0.3 m from the center of the wheel
3 m/s
A wheel turns through an angle of 188 radians in 8.0s; and its angular speed at the end of the period is 44 rad/s. If the angular acceleration is constant, what was the angular speed of the wheel at the beginning of the 8.0s interval?
3.0 rad/s
A grindstone, intially at rest, is given a constant angular acceleration so that it makes 20.0 rev in the first 8 s. What is its angular acceleration?
3.93 rad/s^2
A spinning disc rotating at 130 rev/min slows and stops 31 s later. How many revolutions did the disc make suring this time?
34
A car is moving along a horizontal road at a constant velocity that is directed 45 degrees south of east. What is the direction of the angular velocity of the wheels of the car?
45 degrees north of east
What is the tangential speed of Nairobi, Kenya, a city near the equator? the earth makes one revoluation every 23.93 h and has an equatorial radius of 6380 km.
465 m/s
A bicycle wheel of radius 0.70m is rolling without slipping on a horizontal surface with an angular speed of 2.0 rev/s when the cyclist begins to uniformly apply the breaks. The bicycle stops in 5.0s Through how many revolutions did the wheel rotates during the 5.0 seconds of braking?
5.0 rev
Complete the following statement: The angular measure 1.0 radian is equal to
57.3 degrees
The earth takes slightly less than one day to complete one roation about the axis passing through its poles. The actual time is 8.616 x 10^4 s. Given this information, what is the angular speed of the earth about its axis?
7.292 x 10^-5 rad/s
On an amusement park ride, passengers are seated in a horizontal circle of radius 7.5m. The seats begin from rest and are uniformly accelerated for 21 seconds to a maximum rotational speed of 1.4 rad/s What is the instantaneous tangential speed of the passengers 15 s after the acceleration begins?
7.5 m/s
A circular disk of radius 2.0m rotates, starting from rest, with a constant angular acceleration of 20.0 rad/s^2. What is the tangential acceleration of a point on the edge of the disk at the instant that its angular speed is 1.0 rev/s?
79 m/s^2
During the time a compact disc (CD) accelerates from rest to a constant rotational speed of 477 rev/min, it rotates through an angular displacement of 0.250 rev. What is the angular acceleration of the CD?
794 rad/s^2
A wheel, originally rotating at 126 rad/s undergoes a constant angular deceleration of 5.00 rad/s^2. What is its angular speed after it has turned through an angle of 628 radians?
98 rad/s
A 0.254-m diameter circular saw blade rotates at a constant angular speed of 117 rad/s. What is the tangential speed of the tip of a saw tooth at the edge of the blade?
14.9 m/s
A circular disk of radius 0.015m rotates with a constant angular speed of 5.0 rev/s. What is the acceleration of a point on the edge of the disk?
15 m/s^2
A long thing rod of length 2L rotates with a constant angular acceleration of 8.0 rad/s^2 about an axis that is perpendicular to the rod and passes through its center What is the ratio of the angular speed (at any instant) of a point on the end of the rod to that of a point a distance L/2 from the end of the rod?
1:1
A sculptor is sharpening a chisel on a grindstone of radius 1.0m that is spinning with a constant angular speed of 2.0 rad/s What is the tangentia speed of a point on the rim of the grindstone?
2.0 m/s
A fan rotating with an initial angular velocity of 1000 rev/min is switched off. In 2 second, the angular velocity decreases to 200 rev/min. Assuming the angular acceleration is constant, how many revolutions does the blade undergo during this time?
20
A satellite follows a circular path with constant speed around a planet. Which one of the following quantities is constant and non-zero for this satellite?
Angular Velocity
Two points are located on a rigid wheel that is rotatin with decreasing angular velocity about a fixed axis. Point A is located on the rim of the wheel and point B is halfway between the rim and the axis. Which one of the following statements concerning this situation is true?
Both points have the same instantaneous angular velocity