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: An ice cube goes up a ramp

  1. Dec 14, 2014 #1
    Question statement
    A 55g ice cube can slide without friction up and down a 25∘slope. The ice cube is pressed against a spring at the bottom of the slope, compressing the spring 10cm . The spring constant is 25N/m. When the ice cube is released, what distance will it travel up the slope before reversing direction?

    Relevant equations
    [itex]PE_s = PE_g[/itex]
    [itex]PE_s = 1/2kx^2[/itex]
    [itex]PE_g = mgh[/itex]

    Attempt at a solution
    Maximum height is when all energy is converted to gravitational potential energy (frictionless environment)

    Thus,

    [itex]PE_s = PE_g[/itex]

    [itex]1/2kx^2 = mgh[/itex]

    [itex]1/2(25N/m)(0.1m)^2 = (0.055kg)(9.8m/s^2)(h)[/itex]

    [itex]h = 0.23m[/itex] or [itex] 23 cm[/itex]
    (Answer is asked for in cm)

    Not sure what I am doing wrong here...
     
  2. jcsd
  3. Dec 14, 2014 #2

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    You computing the height, not the distance along the slope.
     
  4. Dec 14, 2014 #3
    I'm so silly. I need to learn to read questions further before answering something different.

    Distance up slope would be
    [itex]0.23(sin 35°) = 0.40m = 40cm[/itex]

    but thats not right!!!

    How do I compute the distance up the slope?
     
  5. Dec 14, 2014 #4

    NTW

    User Avatar

    Wasn't it a 25º slope?
     
  6. Dec 15, 2014 #5
    Yes, it was... Thanks...

    :nb)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Loading...