CHAPTER11

In an isolated system, the moment of inertia of a rotating object is halved. What happens to the angular velocity of the object?

• It remains the same.

• It is halved.

• It is doubled.

• It is quartered.

Answer explanation

A solid sphere and a hollow sphere have the same massand radius. They are rotating with the same angular speed. Which one has the higher angular momentum?

• the solid sphere

• impossible to determine

• both have the same angular momentum

• the hollow sphere

A blob of clay of mass M is dropped on top of a rotating disk's edge of mass 2M spinning at a speed of ω0. What will the resulting rotational speed ω be?

• w = 0.25 w0

• w = w0

• w = 2w0

• w = 0.5w0

Answer explanation

A comet is orbiting a star in a far distant galaxy wth only gravity acting upon it. After a period of time, the sun's radiation partially melts the comet, decreasing the mass to a fourth of what it was. Simultaneously, because of an irregular orbit, its distance to the star doubles. What expression best describes the comet's angular velocity, v, compared to its original conditions (before the melting/distance change)?

• 2v

• 4v

• 0.5v

• v

Answer explanation

The total angular momentum of an object remains constant unless acted upon by an external

• Acceleration

• Force

•  

  Velocity

• Torque

Angular momentum is what type of quantity?

• Vector

•  

  Scalar

• Linear

• Rotational

Both angular velocity and inertia of moment must be at the same rotational line and 

• Axis

• Level

• Point

•  

  Path

A thin ring of mass 5kg and diameter 20cm is rotating about it axis 70rps. Find its angular momentum?

• 11

• 22

• 33

• 44

Answer explanation

The product of torque and angular velocity is ...

• Work

• Angular Momentum

• Power

• Torque