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Question
Calculate the change in the Kinetic energy of a moving body if its velocity is reduced to 1/3rd of the initial velocity.
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Solution
K.E.1 = `1/2 "mv"^2`
K.E.2 = `1/2"m"(1/3"v")^2`
KE1 : KE2
`1/2 "mv"^2= 1/2"m"(1"v"^2)/9`
`"mv"^2/2="mv"^2/18=18:2=9:1`
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