What is the term for the rate of change of angular velocity?

• A. Linear Acceleration
• B. Angular Acceleration
• C. Torque
• D. Moment of Inertia

Answer: (B)

Angular velocity tells you how fast something is rotating and in what direction. The rate at which that spin rate changes is angular acceleration, often denoted alpha. Mathematically, it's the time derivative of angular velocity: alpha = dω/dt, measured in radians per second squared. This tells you how quickly the rotation is speeding up or slowing down. If a torque is applied to a rotating object, it produces angular acceleration proportional to the torque divided by the object’s moment of inertia (τ = Iα). Positive angular acceleration means the rotation rate is increasing, while negative means it’s decreasing. This is the rotational counterpart to linear acceleration, with angular velocity playing the role of velocity and torque playing the role of force.