Perfectly Elastic Collision and final velocity of ball

[Balsam]

Homework Statement

Two balls collide in a perfectly elastic collision. Ball 1 has a mass of 3.5kg and is initially traveling at a velocity of 5.4m/s

. It collides head-on with stationary ball 2 with mass 4.8kg. Determine the final velocity of ball 2.

Given: m1=3.5kg
v_i1=5.4m/s

m2=4.8kg
v_i2=0m/s

Homework Equations

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The Attempt at a Solution

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. I don't know how to solve the problem beyond what I've already done. I'm stuck.​

 

[BvU]

Can't read it. Momentum conservation and conservation of kinetic energy should be enough to work out this exercise. Postpone inserting numbers as long as reasonable, so you can check the relationships you get (dimension, limiting cases).
Type it out if you want more guidance (at least, from folks like me, and also from folks who don't even try to read photographed solution attempts at all).