ROTATIONAL MOTION

What is the role of external forces in determining the motion of the center of mass?

• External forces have no effect
• External forces act only on individual particles
• The center of mass moves as if all external forces act on it
• External forces cancel out

If a system is isolated, what can be said about its center of mass motion?

• It accelerates randomly
• It comes to rest
• It moves in a circular path
• It moves with constant velocity

What is the effect of internal forces on the total linear momentum of a system?

• They increase momentum
• They decrease momentum
• They reverse momentum direction
• They do not change the total linear momentum

For general rotation of a rigid body with one point fixed, what is the reference for the position vector r in v = ω × r?

• The center of the Earth
• The edge of the body
• The highest point of the body
• The fixed point taken as the origin

What is the direction of the angular velocity vector in fixed-axis rotation?

• Tangential to the circular path
• Radially outward
• Opposite to linear velocity
• Along the axis of rotation