A 0.0125 kg bullet strikes a 0.300-kg block attached to a fixed horizontal spring whose spring constant is 2.25 x 103 N/m and sets it into vibration with an amplitude of 12.4 cm. What was the speed of the bullet if the two objects move together after impact? E=(1/2)kA^2=(1/2)(2250 N/m)(0.124 m)2=17.30 J m=0.0125 kg + 0.3 kg=0.3125 kg K=(1/2)mv^2 17.30 J=(1/2)(0.3125 kg)v^2 v2=0.009 v=0.095 m/s Conservation of momentum: (.0125 kg)v=(0.3125 kg)(0.095 m/s) v=2.375 m/s Have I done this properly? The velocity doesn't seem right to me. Have I missed anything?