Centrifugal force is proportional to which quantity?

• A. rotational velocity
• B. mass
• C. radius
• D. angular acceleration

Answer: (A)

Centrifugal force for a mass m at a radius r in a rotation with angular velocity ω has magnitude F = m ω^2 r. This shows the force grows with the square of how fast the system is spinning and with the radius, and scales with the mass. If mass and radius are fixed, the force changes with rotational velocity as F ∝ ω^2, meaning doubling the spin rate makes the force four times larger. You can also see this in terms of tangential speed v = ω r, giving F = m v^2 / r, which reinforces that the force increases with the square of the rotation-related speed. Angular acceleration doesn’t enter the static force expression, so it doesn’t determine the instantaneous centrifugal force; it affects how ω changes over time, not the current magnitude of the force.