12.2.3—A = rω2 and a = v2 / r

For circular motion, centripetal acceleration is a=rω²=v²/r and points radially inward.

Use angular speed or tangential speed consistently, and remember the acceleration is perpendicular to instantaneous velocity in uniform motion.

At r=0.50 m and ω=4.0 rad s⁻¹, a=rω²=8.0 m s⁻².

The object is accelerating even at constant speed because its velocity direction changes.