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: Concept Questions regarding Work

  1. Oct 22, 2008 #1
    1. The problem statement, all variables and given/known data

    Two objects with unequal mass are released from rest from the same height. They slide without friction down a slope and then encounter a rough horizontal region. The coefficient of kinetic friction in the rough region is the same for both masses. The lighter mass will travel further along the rough region before stopping.
    True or False?

    2. Relevant equations

    Work = Force•displacement•cosθ (angle between force and displacement)
    Kinetic Energy = .5•m•v^2
    Potential Gravitational Energy: m•g•h

    3. The attempt at a solution

    The answer is False; but I can't grasp the concept.
  2. jcsd
  3. Oct 22, 2008 #2


    User Avatar
    Homework Helper

    Why not?

    Write out the equation for what happens.

    m*g*h = 1/2*m*v2 - u*m*g*d

    What happens if you divide the equation by m?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook