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: Reduced mass for an infinite mass and a finite mass?

  1. May 3, 2007 #1
    1. The problem statement, all variables and given/known data
    We have a collision between a finite mass steel ball and an infinite mass steel wall and must find the maximum compression if we are given the mass of the ball, the initial speed and the constant b (See eq. below).

    2. Relevant equations
    We know that the maximum compression for two spheres colliding is given by
    Em=((5/4b)uv^2)^5/2 where v is the initial velocity upon collision and u is the reduced mass u=m1m2/(m1+m2). b is a constant.

    3. The attempt at a solution
    Now my only question is what to use as the reduced mass. Mathematically by putting in infinity as m2 we get a reduced mass of 1. Is this correct?
  2. jcsd
  3. May 3, 2007 #2


    User Avatar
    Gold Member

    mathmetically it's: m1.
    but physically you are given that m2>>m1.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook