Angular momentum L = m v r depends on which three quantities?

• A. Mass, velocity, and time
• B. Mass, velocity, and radius
• C. Velocity, radius, and force
• D. Mass, acceleration, and radius

Answer: (B)

Angular momentum for a point particle about a fixed origin comes from the cross product of position and momentum: L = r × p = m (r × v). The magnitude is L = m v r sin(phi), where phi is the angle between the position vector and the velocity. When the motion is perpendicular to the radius (a common case, like circular or tangential motion), sin(phi) equals 1, giving L = m v r. So the quantities that set the angular momentum are the mass, the speed, and the distance from the origin (the radius). Time, force, or acceleration aren’t direct factors in the basic expression; they influence L only by changing v or r.