A 0.308 kg croquet ball makes an elastic head-on collision with a second ball initially at rest. The second ball moves off with half the original speed of the first ball. What is the mass of the second ball?(adsbygoogle = window.adsbygoogle || []).push({});

so i used the formula m1v1initial + m2v2initial = m1v1final + m2v2final

v2initial=0 therefore m1v1initial = m1v1final + m2v2final

i know that v1initial = v1final + v2final

and the questions tells me v2final = (1/2)v1initial

i plug everything in and i get m1(1/2)v1initial = m2(1/2)v1initial

therefore m1 = m2... but it's the wrong answer

anyone know what i did wrong?

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# Homework Help: Collision between two croquet balls

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