Question

The one dimensional complete elastic collision.

If two balls, one 0.03 kg is traveling at 0.2 m/s toward the other one with the opposing speed of 0.4 m/s and the mass 0.01 kg. At what speed does the two balls travel after the collision?

Big ball 0.2--> <--Small ball 0.4

My solution:
The energy in the momentum follows:
0.03*0.2-0.01*0.4=0.01*v1-0.03*v2
But the problem is that I have two variables rendering this function a infinite number of solutions. The same with kinetic energy formula of
m*v^2/2=F. How can I use them together, or am I on the wrong track?

Answer 1

Really neatly done but its about there I get stuck. Right, so I got the two formulas but I don't know how to use them together to get v1 and v2.

Answer 2

You know I think if you solve the first equation to get v1 in terms of v2 and then substitute in the second equation.
Then you'll get a quadratic equation with v2.
Try solving it and see if you get the answer!
:)

Answer 3

Ah I get it. So I narrow it down to just v1 or v2 then solve for it with the second function. Thanks for your help.

Answer 4

Solved it for:
Big Ball 0.1 m/s <-- --> Small ball 0.5 m/s

Answer 5

Ah.. Excellent. :)