Exam 10: Conservation of Angular Momentum

As a particle with a velocity in the negative x direction passes through the point (0,0,1),it has an angular velocity relative to the origin that is best represented by vector

A man stands on the center of a platform that is rotating on frictionless bearings at a speed of 1.00 rad/s.Originally his arms are outstretched and he holds a 4.54-kg mass in each hand.He then pulls the weights in toward his body.Assume the moment of inertia of the man,including his arms,to remain constant at 5.42 kg · m².If the original distance of the weights from the axis is 0.914 m and their final distance is 0.305 m,the final angular velocity is

Two wheels with identical moments of inertia are rotating about the same axle.The first is rotating clockwise at 2.0 rad/s,and the second is rotating counterclockwise at 6.0 rad/s.If the two wheels are brought into contact so that they rotate together,their final angular velocity will be

Consider Earth as a uniform sphere of diameter 12.7 $\times$ 10⁶ m,with a mass of the 5.98 $\times$ 10³⁰ kg,and a rotational period of 1 day.If Earth suddenly had a diameter of half this value without any loss of mass,calculate the new period of rotation.

The velocity a planet of mass m with circular orbit is given by where v_o in m/s is a constant,and $\omega$ is the angular velocity.Its position vector is .The angular momentum of the planet about the center of the orbit is

A spinning bicycle wheel is supported as shown by a line fastened to one end of its axle.The resultant torque acting on the wheel lies along which of the following axes?

The angular momentum of a body about a particular axis as a function of time is shown in the graph.The external torque acting on the body along this axis at t = 2 s is

A constant torque of 15 N · m acts for 3.0 s on a system of mass 2.0 kg.The change in angular momentum of the system during this period of time is

A disc rotates clockwise in the plane of the page.What is the direction of the angular momentum vector?

The angular momentum of a rotating object is initially and 2s later it is .The units are in kg.m²/s.The torque that produces the change in angular momentum is

A wheel is set spinning and then is hung by a rope placed at one end of the axle.The precession vector of the spinning wheel points in the direction of

Which of the following are required for the total momentum (both angular and linear)of a system to be conserved?

Vectors and lie in the xy plane.The vector product $\times$ ( $\times$ )could be represented by vector

Which of the following statements is not true?

If the distance between two hydrogen atoms of H₂ is 0.1 nm,what is its E_0r?

A gyroscopic wheel spins clockwise as shown.The set of vectors that correctly describes the directions of the torque ,angular momentum ,and angular velocity of precession _p,is

A gyroscopic toy is spinning as shown.The torque $\tau$ ,angular momentum of the wheel ,and angular precession velocity $\omega$ _p are in which directions?

A disc with moment of inertia I₁ = 40 kg.m² and angular velocity $\omega$ ₁ = 20 rad/s is dropped on to a stationary second disc along the axis of rotation.The second disc has moment of inertia I₂ = 60 kg.m².What is the angular velocity of the two discs?

If the sum of the torques on a body about a fixed axis is not zero,the body most certainly

The propeller of a motorboat turns clockwise relative to a water skier being towed by the boat.As the boat makes a sharp turn to the left,gyroscopic action tends to