normal acceleration[′nȯr·məl ak‚sel·ə′rā·shən]
the component of acceleration for a point in curvilinear motion that is directed along the principal normal to the trajectory toward the center of curvature; normal acceleration is also called centripetal acceleration. It is numerically equal to v2/ρ, where v is the velocity of the point and ρ is the radius of curvature of the trajectory. For circular motion the normal acceleration can be calculated from the formula rω2, where r is the radius of the circle and ω is the angular velocity of rotation of the radius. For rectilinear motion the normal acceleration is zero.
ii. The usual or typical acceleration.