Question

A $500$ Newton girl (just over $110$ pounds) stands on a scale in an elevator. She is heading up to the tenth floor, and the elevator is slowing to a stop with a constant acceleration of $2m/s^2$.
About how much does the scale read as the elevator is stopping?

• A. $400N$
• B. $600N$
• C. $500N$
• D. $1000N$
• E. $0N$

Answer 1

The correct option is A $400N$

Given : $a=2$ $m/s^2$

Actual weight of girl $W=500$ N

Thus mass of the girl $m=\frac{W}{g}=\frac{500}{10}=50$ kg

As the elevator is slowing while moving in upward direction, thus is has acceleration in the downward direction.

Vertical direction : $ma=W-N$

$\therefore$ Apparent weight of girl $N=W-ma=500-50\times 2=400$ N