MCQ
The weight of man in a lift moving upward is $608\,N$ while the weight of the same man in the lift moving downwards with the same acceleration is $368\, N$. His normal weight is ............ $ N$
- A$480$
- ✓$488$
- C$588$
- D$240$
✓
Answer
Correct option: B.
$488$
b
When the lift accelerates at a upwards
When the lift accelerates at a upwards
$\mathrm{m}(\mathrm{g}+\mathrm{a})=608$ $...(i)$
When the lift accelerates at a downwards
$m(g-a)=368$ $...(ii)$
From $(i)$ and $(ii)$ we geta $=2.4 \mathrm{m} / \mathrm{s}^{2}$
$m=49.8 \mathrm{kg}$
The normal weight $=\mathrm{mg}$
${w=49.8 \times 9.8}$
${w=488 \mathrm{N}}$
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