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A barometer kept in an elevator reads 76...

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

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Let `a` be the acceleration of the elevator and `h` be the barometer height then
`P_(a)=rho(g+a)h`……..i
For the static elevator with barometric height `h_(0)`
`P_(a)=rhogh_(0)`……….ii
From eqn i and ii get
`h=(gh_(0))/((g+a))`
Clearly `hlth_(0)` so barometric reading in an acelerating elevator will be less than `76 cm`.
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