Q. A 10.8 kg weather rocket generates a thrust of 250-N. The rocket, pointing upward, is clamped to the top of a vertical spring. The bottom of the spring, whose spring constant is 407-N/m, is anchored to ground. At first, before the engine is ignited, rocket sits at rest on top of the spring. After the engine is ignited, what is the rocket's speed while the spring has stretched 15.80 cm past its natural length? What would be rockets speed after travelling the distance if it weren't tied down to the spring?