Q1. A boy sits on a rotating chair (without friction) which is rotating at an angular speed of 2 rev/s. His arms are outstretched and he holds a brick in each hand. The moment of inertia of the system (boy + bricks + chair) in this configuration is 5.0 kg.m^2. He decreased the moment of inertia of the system to 2.5 kg m^2 by moving the bricks. What is the resulting angular speed in rpm units? * 130 rpm 360 rpm O 240 rpm O Not given 211 rpm

Q1. A boy sits on a rotating chair (without friction) which is rotating at an angular speed of 2 rev/s. His arms are outstretched and he holds a brick in each hand. The moment of inertia of the system (boy + bricks + chair) in this configuration is 5.0 kg.m^2. He decreased the moment of inertia of the system to 2.5 kg m^2 by moving the bricks. What is the resulting angular speed in rpm units? * 130 rpm 360 rpm O 240 rpm O Not given 211 rpm

University Physics Volume 1

18th Edition

ISBN:9781938168277

Author:William Moebs, Samuel J. Ling, Jeff Sanny

Publisher:William Moebs, Samuel J. Ling, Jeff Sanny

Chapter10: Fixed-axis Rotation

Section: Chapter Questions

Problem 101P: A propeller is accelerated from rest to an angular velocity of 1000 rev/min over a period of 6.0...

See similar textbooks

Similar questions

With the aid of a string, a gyroscope is accelerated from rest to 32 rad/s in 0.40 s under a constant angular acceleration. (a) What is its angular acceleration in rad/s2 ? (b) How many revolutions does it go through in the process?
Integrated Concepts An ultracentrifuge accelerates from rest to 100,000 rpm in 2.00 min. (a) What is its angular acceleration in rad/s2? (b) What is the tangential acceleration of a point 9.50 cm from the axis of rotation? (c) What is the radial acceleration in m/s2 and multiples of g of this point at full rpm?
(a) What is the angular speed of the second hand of a clock? (b) What is the direction of as you view a clock hanging on a vertical wall? (c) What is the magnitude of the angular acceleration vector of the second hand?
During a 6.0-s time interval, a fly-wheel with a constant angular acceleration turns through 500 radians that acquire an angular velocity of 100 rad/s. (a) What is the angular velocity at the beginning of the 6.0 s? (b) What is the angular acceleration of the fly-wheel?
A baseball catcher extends his arm straight up to catch a fast ball with a speed of 40 m/s. The baseball is 0.145 kg and the catcher’s arm length is 0.5 m and mass 4.0 kg. (a) What is the angular velocity of the arm immediately after catching the ball as measured from the arm socket? (b) What is the torque applied if the catcher stops the rotation of his arm 0.3 s after catching the ball?
A cylinder with moment of inertia I1 rotates with angular velocity 0 about a frictionless vertical axle. A second cylinder, with moment of inertia I2, initially not. rotating, drops onto the first cylinder (Fig. P8.73). Because the surfaces are rough, the two cylinders eventually reach the same angular speed . (a) Calculate . (b) Show that kinetic energy is lost in this situation, and calculate the ratio of the final lo the initial kinetic energy. Figure P8.73
A propeller is accelerated from rest to an angular velocity of 1000 rev/min over a period of 6.0 seconds bya constant torque of 2.0103Nm . (a) What is the moment of inertia of the propeller? (b) What power is being provided to the propeller 3.0 s after it starts rotating?
A small ball of mass 0.50 kg is attached by a massless sting to a vertical rod that Is spinning as shown below. When the rod has an angular velocity of 6.0 rad/s, the sting makes an angle of 30 with respect to the vertical. (a) If the angular velocity is increased to 10.0 rad/s, what is the new angle of the string? (b) Calculate the initial and final angular momenta of the ball. (c) Can the rod spin fast enough so that the ball is horizontal?
With the aid of a string, a gyroscope is accelerated from rest to 32 rad/s in 0.40 s. (a) What is its angular acceleration in rad/s2? (b) How many revolutions does it go through in the process?
There an analogy between rotational and physical quantities. What rotational quantities are analogous to distance and velocity?
Gyroscopes used in guidance systems to indicate directions must have an angular momentum that does not change in direction. Yet they are often subjected to large and accelerations. How can the direction of their angular momentum be constant when they are accelerated?
Olympic ice skaters are able to spin at about 5 rev/s. (a) What is their angular velocity in radians per second? (b) What is the centripetal acceleration of the skater's nose if it is 0.120 m from the axis of rotation? (c) An exceptional skater named Dick Button was able to spin much faster in the 1950s than anyone since—at about 9 rev/s. What was the centripetal acceleration of the tip of his nose, assuming it is at 0.120 m radius? (d) Comment on the magnitudes of the accelerations found. It is reputed that Button ruptured small blood vessels during his spins.