A lift coming down is just about to reach the ground floor. Taking the ground floor are origin and positive direction upwards for all quantities, which one of the following is correct?

Options

A. `xlt0,vlt0,agt0`
B. `xgt0,vlt0,alt0`
C. `xgt0,vlt0,agt0`
D. `xgt0,vgt0,agt0`

Answer

A

Explanation

As the lift is coming down, the value of x becomes less hence negative (i.e,`x lt0`).
Velocity is downwards (i.e., negative). So `v lt 0`.
Just before reaching ground floor, lift is retarded, i.e, acceleration is upwards, Hence `a gt 0`.
We can conclude that `x lt0 ,v lt 0 `and `a gt0`. `thereofore` (a) is correct.