ROTATIONAL MOTION

What determines the trajectory of the center of mass of a projectile?

• Internal energy of the system
• Shape of the object
• Color and temperature
• Initial velocity and external forces like gravity

How does the explosion of a firecracker in mid-air demonstrate the conservation of momentum?

• All pieces fall vertically
• The explosion stops horizontal motion
• Pieces move in random uncorrelated paths
• The center of mass follows the original parabolic path despite fragmentation

If a system of particles has zero total momentum, what can be said about the center of mass?

• All particles must be at rest
• The system is unstable
• The center of mass is accelerating
• It is either at rest or moving with constant velocity

What is the role of the center of mass in analyzing the motion of extended bodies?

• It eliminates the need for forces
• It stops all rotation
• It doubles the kinetic energy
• It allows the body to be treated as a point mass for translational motion

What is the direction of the total momentum vector in a system where particles move in different directions?

• Randomly oriented
• Opposite to center of mass
• Perpendicular to center of mass motion
• Same as the direction of the center of mass velocity