When a rigid body is undergoing purely translational motion, which of the following statements are true? (Select all that apply) When a rigid body is undergoing purely translational motion, which of the following statements are true? (Select all that apply) Rotational forces play a significant role in the translation of the body. The sum of external forces equals the mass of the body times the acceleration of the center of mass. The acceleration of the body is different at different points on the body. The body's motion can be described by the motion of its center of mass alone. External forces acting on the body do not affect its translational motion