ROTATIONAL MOTION

How is the total torque on a system of particles expressed in terms of external and internal contributions?

• τ = τ_ext × τ_int
• τ = τ_ext − τ_int
• τ = τ_ext + τ_int
• τ = τ_int / τ_ext

What is the primary reason internal torques sum to zero in a system of particles?

• Internal forces are negligible
• Internal forces rotate the center of mass
• Internal forces are equal, opposite, and act along the line joining the particles
• Internal forces depend on velocity

How does torque affect direction of angular momentum?

• It only changes magnitude
• It only changes direction
• It has no effect
• It can change both magnitude and direction

How does a gyroscope maintain orientation?

• Due to gravity
• Due to friction
• Due to magnetic field
• Due to conservation of angular momentum

What happens to angular momentum in an explosion in space?

• L is lost
• L increases
• Total L remains unchanged if no external torque
• L becomes zero