- #1
gibberingmouther
- 120
- 15
Homework Statement
"For a two-particle interaction, the relative velocity between the two vectors is independent of the choice of relatively inertial reference frames."
and
"The change in kinetic energy is independent of the choice of relatively inertial reference frames."
My textbook says that if you look at the velocities of a two particle elastic interaction before and after the collision, regardless of which reference frame you choose, the relative velocities before and after will be the same. It just says this, and I guess expects you to make an intuitive leap? I wanted a more mathematical explanation which is why i looked on the internet and found the MIT page. The professor gives an example in the case of a two particle interaction where the one particle is twice the mass of the other, and shows that in this case the relative velocities will be the same. Cool, but i wasn't really satisfied.
Anyway, besides hoping for a better explanation of the relative velocities in an elastic collision, I was also confused by the terminology of "a relatively inertial reference frame". I want to read and understand the MIT pdf but i need to be able to know what that terminology means first. I am also hoping someone could help me by explaining the two statements from the pdf i quoted above.
http://web.mit.edu/8.01t/www/materials/modules/chapter15.pdf
Homework Equations
conservation of kinetic energy and conservation of momentum.
The Attempt at a Solution
i tried to imagine two coordinate systems moving relative to each other and the velocities being different while the relative velocities are the same. couldn't quite manage it. maybe i should drink more coffee, lol? I'm grateful for my intelligence but I'm not quite an Einstein :(
i was able to read some of the math in the MIT pdf but still trudging through, just need to get unstuck on the parts i mentioned above.