Question

A barometer kept in an elevator reads $76cm$ when it is at rest. What will be barometric reading when the elevator accelerates upwards?

• A. $\frac{(g+a)h_0}{g}$
• B. $\frac{g{h}_0}{g+a}$
• C. $\frac{a}{g}{h}_0$
• D. $\frac{g}{a}{h}_0$

Answer 1

The correct option is A $\frac{(g+a)h_0}{g}$

When a body moves upward the acceleration due to gravity is,

$g^{\prime }=g+a$

Hence, the pressure is

$P=h_0\rho \left(g+a\right)$

$=\frac{h_0\left(g+a\right)}{g}$

Hence, the barometer reading will be more than the measured value at rest.