Recent content by Philippe007

Oh i think its because i used KEf = 1/2m1(v1f)^2 + 1/2m2(v2f)^2 Wouldnt that be right?

So, I did what you said, and its starting to look like an answer, thanks for that. But now I have: u1x = (u1x)^2 ((1839/1841)^2 + (1840)(2/1840)^2) with the left side being inital and the right side being the final KE's I was wondering though, how would I convert that into a percentage?

Ok: u1x = v1x + 1840v2x u1x = v2x - v1x so... v2x= u1x + v1x and then... u1x = v1x + 1840(u1x + v1x) u1x = v1x + 1840u1x + 1840v1x -1839u1x = 1841v1x u1x = -1841v1x/1839 there. What is this even showing me. I have still have 2 unknowns?

You did say to combine the equations. But, when you do solve for u1, there are still 2 variables, and you can't find the KEf or KEi without at least one of these, and therefore can't compare the two.

So your saying that when you add the equaitons and get: V1i = 1841v2f How can this be used to compare the two KE? since KEi = (1/2)mv^2 KEi = (1/2)(1)(1841v2f)^2 It doesn't give an actual number, and again there ends up with two variables and then KEf would be: KEf =...

I have tried combining the two equations, but that only gives me a new equation with two unknown velocities, and I need all three velocities to find the inital and final KE. How would I use an equation with 2 unknown variables to compare the initial and final KE?? Help??

Homework Statement An electron collides elastically with a hydrogen atom that is initially at rest. Assume all the motion occurs along a straight line. What fraction of the electron's initial kinetic energy is transferred to the atom? (Take the mass of the hydrogen atom to be 1840 times the...