(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A ball of mass 20.0kg (mass A) traveling at a initial speed of 5.0m/s, collides with a ball of mass 10.0kg (mass B) which was traveling at a initial speed of 1.0m/s. What is the final velocity of mass A, what is the final velocity of mass B?

mA = 2mB

2. Relevant equations

ΣFext = 0

Δp = 0

ΔEk = 0

quadratic equation

3. The attempt at a solution

I am unsure how to find the final velocities here because I have two variables and I have to use the quadratic equation to find the final velocities right? So I was just wondering if I could somehow isolate and get rid of a variable, this is what I have so far:

Δp=0

PiA + PiB = PfA +PfB

mAviA + mBviB = mAvfA + mBvfB

mAviA + 2mAviB = mAvfA + 2mBvfB

viA + ViB = vfA + vfB

(5.0) + (1.0) vfA + vfB

6.0-vfA = vfB

Then I put it into the kinetic energy equation and put in all the numbers and I got as an answer:

510.0 = (20.0)(vfA)(squared) + (10.0)(vfB)(squared)

My question is basically how am I supposed to incorporate this into the quadratic equation to find the final velocities?

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# Homework Help: What is the final velocity of mass

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