The angular momentum of a system remains constant A) when the ...

[cabate]

The angular momentum of a system remains constant
 
  A) when the total kinetic energy is constant.
  B) when no net external force acts on the system.
  C) when the linear momentum and the energy are constant.
  D) when no torque acts on the system.
  E) all the time since it is a conserved quantity.

Question 2

A uniform disk, a uniform hoop, and a uniform solid sphere are released at the same time at the top of an inclined ramp. They all roll without slipping. In what order do they reach the bottom of the ramp?
 
  A) disk, hoop, sphere
  B) hoop, sphere, disk
  C) sphere, disk, hoop
  D) sphere, hoop, disk
  E) hoop, disk, sphere

[Hdosisshsbshs]

Answer to Question 1

Answer: D

Answer to Question 2

Answer: C