Agent Arlene devised the following method of measuring the muzzle velocity of a rifle. She fires a bullet into a 4.400-kg wooden block resting on a smooth surface, and attached to a spring of spring constant k = 137.0N/m . The bullet, whose mass is 7.800g, remains embedded in the wooden block. She gauges the maximum distance that the block compresses the spring to be 9.460 cm. What is the speed v of the bullet?