Question

write the relation between angular accleration and linear accleration

Answer 1

angualar acceleration = r×angular acceleration

Answer 2

If an object is rotating at angular velocity ωω and angular acceleration αα, then a point at distance rr from the axis of rotation will have speed v=rωv=rω, tangential acceleration at=rαat=rα, and centripetal acceleration ac=rω2ac=rω2.  The linear acceleration of that point is the vector sum of these two perpendicular components of the acceleration.