A massless spring (with force constant k = 189 N/m) connects a wall and a block of wood. The system is initially at rest, with the spring unstretched. The block has mass M = 53.7 g and is able to move without friction on a table. A gun is positioned to fire a bullet of mass m = 7.7 g into the block along the spring axis. After the gun is fired, the bullet gets embedded in the block, and the spring is compressed a maximum distance d = 0.89 m. In meters per second, what is the speed of the bullet v before it enters the block?

A massless spring (with force constant k = 189 N/m) connects a wall and a block of wood. The system is initially at rest, with the spring unstretched. The block has mass M = 53.7 g and is able to move without friction on a table. A gun is positioned to fire a bullet of mass m = 7.7 g into the block along the spring axis. After the gun is fired, the bullet gets embedded in the block, and the spring is compressed a maximum distance d = 0.89 m. In meters per second, what is the speed of the bullet v before it enters the block?