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Question
A barometer kept in an elevator reads 76 cm when it is at rest. If the elevator goes up with increasing speed, the reading will be ______.
Options
zero
76 cm
< 76 cm
> 76 cm
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Solution
A barometer kept in an elevator reads 76 cm when it is at rest. If the elevator goes up with increasing speed, the reading will be > 76 cm.
If the elevator goes up at an increasing speed, then the effective value of g increases.
We know:
P = ρgh
So, h will have a lesser value for the same value of P if g increases.
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