Two balls with masses in the ratio of 1 : 2 moving in opposite direction have a head a head - on elastic collision. If their speeds before impact were in the ratio of 3 : 1 respectively, then speeds after impact will have the ratio:
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pi = pf ⟹ m × 3v – 2m × v = mv1' + 2mv2'
v = v1' + 2v2' ... (1)
..........(2)
(1) + (2) :
.