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प्रश्न
उत्तर
K.E ,K = `1/2` mv²
If mass is increased four times
K.E ,K' = `1/2` (4m) (v)²
or K' = 4 x `1/2`mv²
to maintain the same kinetic energy the velocity should be made half.
Then, K" = 4 x `1/2` m `("v"/2)²` = K
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