1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Spring and Energy: Rocket clamped to an anchored spring

  1. Apr 18, 2017 #1


    User Avatar

    1. The problem statement, all variables and given/known data
    A 11.6 kg weather rocket generates a thrust of 200 N . The rocket, pointing upward, is clamped to the top of a vertical spring. The bottom of the spring, whose spring constant is 580 N/m , is anchored to the ground.

    Initially, before the engine is ignited, the rocket sits at rest on top of the spring. How much is the spring compressed?

    After the engine is ignited, what is the rocket's speed when the spring has stretched 32.0 cm ?

    For comparison, what would be the rocket's speed after traveling this distance if it weren't attached to the spring?

    2. Relevant equations:

    3. The attempt at a solution:
    I found 0.1962m for part A
    but part B and C, I don't think I am on the right track. I don't know how to use LaTex, so hopefully you understand

    for question b:
    I used conservation of energy of the spring systems, saying 1.2mv^2=1/2 k* delta(x)^2
    delta x I used 0.1962m of part A to solve for v by all given variables

    for part c:
    my answer was funky. I found net acceleration on y direction and then used integral to solve for v, but it was not working.
  2. jcsd
  3. Apr 18, 2017 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Conservationof energy says initial total energy equals final total energy. Does that match your equation?

    (You will not be able to use conservation of energy here. Consider forces and accelerations.)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted