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A body is thrown up in a lift with a vel...

A body is thrown up in a lift with a velocity `u` relative to the lift, and returns to the lift in time `t`. Show that the lift`s upward acceleration is `(2u-gt)/(t)`.

Text Solution

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Relative to the lift, initial velocity of the bod `=u`,
Acceleration of the body `=g+a`
Net displacement of the body `y=0`.
`becuase` Using `s=ut+(1)/(2)a t^(2)`
`0=ut-(1)/(2) (g+a)t^(2) rArr t!=0`
`g+a=(2u)/(t) rArr a=(2u-g t)/(t)`.
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