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Two perfectly elastic spheres of masses 2 kg and 3 kg moving in opposite directions with velocities 8 ms^(-1) and 6 ms^(-1) respectively collide with each other. Find their velocities after the impact. |
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Answer» SOLUTION :Here `m _(1) = 2 kg, m _(2) = 3 kg , u _(1 = 8 ms ^(-1) , u _(2) = - 6 ms ^(-1)` According to the LAW of conservation of linear MOMENTUM `, m_(1) u _(1) + m_(2) u_(2) = m_(1) v _(1) + m_(2) v_(2)` i.e., `(2) (8)+ (3) (-6) =2v _(1) + 3 v _(2) implies 2v _(1) + 3v _(2) =-2 ""...(i)` SINCE the collision is elastic,` u _(1) - u _(2) = v _(2) -v _(1)` i.e., `8- (-6) =v _(2)-v_(1) implies v _(2) -v _(1) =14""...(ii)` On solving the equations (i) and (ii) we GET `v _(1) = - 8.8 ms ^(-1), v _(2) = 5.2 ms ^(-1)` |
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