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A lift is coming from 8th floor and it j...

A lift is coming from 8th floor and it just a about to reach 4th flor. Taking ground floor as origin and positive direction upwards for all quantities, which one of the following is correct ?

A

`x lt 0, v lt 0, a gt0`

B

`x gt 0, v lt 0, a lt 0`

C

`x gt 0, v lt 0, a gt 0`

D

`x fr 0, v gt 0 , a lt 0`

Text Solution

Verified by Experts

The correct Answer is:
A
`x lt 0, v lt 0, a gt 0`
As the lift is coming in downward directions displacement will be negative. We have to see whether the motion is accelerating or retarding.
We know that due to downward motion displacement will be negative. When the lift reaches 4th floor it is about to stop hence, motion is retarding in nature hence, `x lt 0, a gt 0.`
As displacement is in negative direaction, velocity will also be negative i.e., `v lt 0.`
THis can be shown on the adjacent graph.
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