Aphysics student devised the following method of measuring the muzzle velocity of a rifle: she fires a bullet into a 4.648 kg wooden block resting on a horizontal smooth surface, and attached to a spring of spring constant k = 142.7 n/m. the bullet, whose mass is 7.87 g, remains embedded in the wooden block. she measures the maximum distance that the block compresses the spring to be 9.46 cm. what is the initial speed of the bullet?