Question

A 11.6 kg weather rocket generates a thrust of 215.0 N. The rocket, pointing upward, is clamped to the top of a vertical spring. The bottom of the spring, whose spring constant is 399.0 N/m, is anchored to the ground. Initially, before the engine is ignited, the rocket sits at rest on top of the spring.

a)How much is the spring compressed?
b)After the engine is ignited, what is the rocket's speed when the spring has stretched 16.1 cm past its natural length?
c)What would be the rockets speed after travelling the distance if it weren't tied down to the spring?

Answer 1

a)
f=-kx
f=>11.6*(-9.8)=-399.0x
solve for x
x=0.285m