Question

A Woman weighing 50 kg stands on a weighting machine placed in a lift. What will be the reading of the machine, When the lift is (i) moving upwards with a uniform velocity of $5m{s}^{-1}$ and (ii) moving downwards with a uniform acceleration of $1m{s}^{-2}?$ $[Take$ $g=10m{s}^{-2}].$

Answer 1

$N+ma=mg$ where $ma$ is the pseudo force.

$⟹N=m(g-a)=$ weight read by machine

$\left(a\right)a=0$

$⟹N=mg=50\times 10=500N$

$\left(a\right)a=1$

$⟹N=m(g-a)=50\times 9=450N$