Question

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

• A. $x<0,v<0,a>0$
• B. $x>0,v<0,a<0$
• C. $x>0,v<0,a>0$
• D. $x>0,v>0,a<0$

Answer 1

The correct option is B $x>0,v<0,a<0$

From the given data,
$4^{th}$ floor is above ground floor
$\therefore X>0$
Lift is approaching ground from $8^{th}$ floor
$\therefore \upsilon <0$
(i.e., direction of velocity)
Lift will accelerate in negative direction
$\therefore a<0$
$\therefore$ Option B
$X>0,\upsilon <0,a<0$