InterviewSolution
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InterviewSolution
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Two blocks of masses `10kg and 20kg` moving at speeds of `10ms^(-1) and 20ms^(-1)` respectively in opposite direction approach each other and colide .If the collision is completely inelastic , find the thermal energy developed in the process |
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Answer» Correct Answer - C `m_(1) = 10kg,V_(1) = 10m//s` `m_(2) = 20kg,V_(2) = 20m//s` Here `m_(2)V_(2) - m_(1)V_(1) = (m_(1) + m_(2))V` `rArr 20 xx 20 - 10 xx 10 = (10 + 20)V` `rArr 400 - 100 = 30V` rArr 300 = 30V` rArr V =10m//s` Initial kinetic energy `= (1)/(2) m_(1)u_(1)^(2)+ (1)/(2)m_(2)u_(2)^(2)` `= (1)/(2) xx 10 xx (10)^(2) + (1)/(2) xx 20 xx (20)^(2)` ` = 500 + 4000 = 4500` Final kinetic energy `= (1)/(2) (m_(1) +m_(2))V^(2)` `= (1)/(2) (10+20)(10)^(2)` `= ((30)/(2)) xx 100 = 1500` THe total change on K.E.`= 4500 - 1500= 3000J` The thermal enrgy devloped in the process `= 3000J` |
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