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: Velocity of center of mass

  1. Sep 30, 2007 #1
    1. Recall that the blocks can only move along the x axis. The x components of their velocities at a certain moment are v1x and v2x. Find the x component of the velocity of the center of mass (vcm)x at that moment. Express your answer in terms of m1, m2, v1x, and v2x

    2. Keep in mind that, in general: v= dx/dt.

    3. its the derivative of xcm = (m1x1 + m2x2) / (m1 + m2)...so does vcm= [(m1)(v1x) + (m2)(v2x)] / (m1 + m2) ?
  2. jcsd
  3. Sep 30, 2007 #2


    User Avatar
    Homework Helper

    yes. looks right to me.
  4. Oct 31, 2010 #3
    what if you dont have the masses, cause im stuck on one question that has just 2 velocities going in the positive x direction
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook