ROTATIONAL MOTION

Is the angular momentum of a two-particle system moving in opposite directions on parallel paths the same about any point?

• No
• Only in vacuum
• Depends on observer
• Yes

Two particles of mass m and speed v move in opposite directions along parallel lines separated by distance d. What is the magnitude of total angular momentum about a point midway between the lines?

• mvd/2
• mvd
• 2mvd
• zero

For a particle in x-y plane motion, why is angular momentum only in z-direction?

• Due to gravity
• Because motion is linear
• Rotation is about z-axis
• Because z-components of r and p are zero

If a particle moves only in the x-y plane, which component of angular momentum is non-zero?

• Only x-component
• Only y-component
• Both x and y components
• Only z-component

What are the components of angular momentum l of a particle with position vector r and momentum p?

• r · p
• p × r
• r + p
• r × p