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: Two masses on a spring...

  1. Apr 5, 2016 #1
    1. The problem statement, all variables and given/known data
    Two masses A, and B both sit on a vertical spring. If the spring is compressed then released, why do A and B rise to the same height? (the mass of A is greater than that of B)

    2. Relevant equations
    P = mgh
    S = 1/2kx2
    K = 1/2mv2

    3. The attempt at a solution
    Both masses rise to the same height, I treated the two blocks as a system, because the spring propels them both in the air. Why is this? How much energy does each block have?
     
  2. jcsd
  3. Apr 5, 2016 #2

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Would you expect them to be travelling at the same speed when contact with the spring is lost?
     
  4. Apr 5, 2016 #3
    Intuitively yes?
     
  5. Apr 5, 2016 #4

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Ok, so using the SUVAT equations, what determines the height to which a projectile rises?
     
  6. Apr 6, 2016 #5
    Initial velocity
     
  7. Apr 6, 2016 #6

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Putting that together with your answer in post #3, does that answer your question?
     
  8. Apr 6, 2016 #7
    Yes! But from an energy point of view, mass A has more energy right?
     
  9. Apr 6, 2016 #8

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted