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/work problem

  1. Oct 20, 2004 #1
    This is the problem:
    A 235g block is pressed against a spring (with K=1.32KN/M) until the block compresses the spring 10.0cm. The spring rests at the bottom of a ramp inclined at 53.4deg to the horizontal.

    A) Using energy considerations, determine how far up the incline the block moves before it stops if there is no friction between the block and the ramp.

    I've draw a free body diagram and setup the problem like this,

    Forces in x dir: Force of spring(Fs)-MgSIN(53.4)
    Forces in y dir: Normal (N)- MgCOS(53.4)=0

    Work due to spring-work due to gravity = K(final)-K(inital) , K(inital)=0 since V=0

    So, (1/2)Kx^2 -(MgSIN(53.4))(x) =1/2 mV^2 (where x = .10 meters)

    I solve for V to find out the speed at the equilibrium point and then use:

    V^2(final)= V^2(inital) + 2ad to find the distance it travels after that,
    (I use a= -gSin(53.4) for this,)

    anyways I keep getting the wrong answer and I don't know where I went wrong? I'd really appericiate if someone could show me where I'm getting messed up.

    P.S. sorry for the long post I'm not really sure how to write alot of this stuff out on the computer.
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted