A man weighs $80 \mathrm{~kg}$. He stands on a weighing scale in a lift which is moving upwards with a…

A man weighs $80 \mathrm{~kg}$. He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of $5 \mathrm{~m} / \mathrm{s}^2$. What would be the reading on the scale? $\left(g=10 \mathrm{~m} / \mathrm{s}^2\right)$
  1. zero
  2. $400 \mathrm{~N}$
  3. $800 \mathrm{~N}$
  4. $1200 \mathrm{~N}$

Solution

Reading of weighing scale $\begin{aligned} & =m(g+a) \\ & =80(10+5)=1200 \mathrm{~N} \end{aligned}$

Asked in: NEET 2003

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