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Question
A bullet is of mass 'm' g and is moving with a velocity 'v' m/s. Find the kinetic energy of the bullet when
(a) The mass is doubled,
(b) The velocity is tripled.
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Solution
K.E of the bullet = `1/2` mv2
(a) If the mass is doubled,
K.E' = `1/2`(2m) v2 = `2 xx 1/2`mv2 = 2K.E
`"K.E"/"K.E" = 2/1`
(b) If the velocity is tripled,
K.E = `1/2` m(3v)2 = 9 x `1/2` mv2
`"K.E"/"K.E" = 9/1`
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