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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).

A

`(u-"gt")/(t)`

B

`(2u-"gt")/(t)`

C

`(u+"gt")/(t)`

D

`(2u+"gt")/(t)`

Text Solution

Verified by Experts

The correct Answer is:
B
`y = u_(y) t +(1)/(2)a_(y)t^(2) rArr 0 = ut - (1)/(2) (g +a)t6(2)`
`u = (1)/(2) (g+a)t rArr a = (2u)/(t) - g rArr a = (2u -"gt")/(t)`
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