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A ball of mass 100 gm is projected upwar...

A ball of mass 100 gm is projected upwards with velocity `(10 m//s)`. It returns back with `(6 m//s)`. Find work done by air resistance .

Text Solution

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The correct Answer is:
B, C
From work energy thergy theorem,
`W_("net") =W_("mg") + W_("air") =1/2m(v_(f)^(2)-v_(i)^(2))`
`rArr 0 + W_(air) =1/2xx0.1[(6)^(2)-(10)^(2)]=-3.2J`
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Knowledge Check

  • A body of mass 50 kg is projected vertically upward with velocity of 100 m//s . After 5 s this body breaks into 20 kg and 30 kg . If the 20 kg piece travels upwards with 150 m//s , then the velocity of other block will be

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    D
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    D
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