ROTATIONAL MOTION

What is the primary reason the center of mass concept is useful in physics?

• It measures the size of the object
• It tells the color of the object
• It allows complex systems to be treated as point masses
• It counts the number of particles

A man stands on a raft floating on water. If he walks to one end, what happens to the raft?

• It stays still
• It moves forward
• It moves in the opposite direction
• It sinks

Where is the center of mass of a uniform cone (solid) from its apex?

• h/2 from the apex
• 2h/3 from the apex
• 3h/4 from the apex
• h/4 from the apex

If all particles in a system move with the same velocity, what is the velocity of the center of mass?

• Zero
• Half of it
• Same as the particle velocity
• Twice of it

A system consists of particles with positions and masses. The sum of mass times position vectors is S, and total mass is M. What is the center of mass?

• S*M
• S+M
• S/M
• M/S