A small block of mass 65 g is released from rest at the top of a curved frictionless wedge of mass 381 g which sits on a frictionless horizontal surface as shown. The acceleration due to gravity is 9.81 m/s². Right is the positive direction. When the block leaves the wedge, its velocity is 2.88 m/s to the right. What is the velocity vb of the wedge after the block reaches the horizontal surface?