F\" A SD-gram mass hangs at the end of the spring; When 20 grams more are added to the end of the spring, it stretches 7" cm more. Find the spring constant. 2.8 2.9 4.3 Which statement/s is/are true for translation? (Kinematics of Rigid Bodies) A. In rectilinear translation, the velocity and acceleration are constant at all instances of the motion. B. In curvilinear motion, velocity and acceleration are constant all throughout the motion. C. In curvilinear motion, the velocity and acceleration of all points in the body are the same at each instant.In rotation; what is true when the angular acceleration is zero? [Kinematics of Rigid Bodies] A. angular velocity is constant B. normal acceleration of the rigid body is zero C. tangential acceleration is zero