Two identical carts collide in three experiments on a low-friction track. In each case, cart A initially has velocity \(\vec{v}\) and cart B is at rest. Sketch the velocity-versus-time graph for each cart \((a)\) if the carts stick together after the collision, (b) if cart A is stationary after the collision, and \((c)\) if cart A has velocity \(-\vec{v} / 10\) after the collision.