Consider the equations P= _ 0 F and P_1-P_2-pgz In an elevator ac… - Vidyadip

Question

Consider the equations

$\text{P}=\lim_\limits{\triangle\text{s}\rightarrow0}\frac{\text{F}}{\triangle\text{s}}$ and $\text{P}_1-\text{P}_2-\text{pgz}$

In an elevator accelerating upward.

Both the equations are valid.
The first is valid but not the second.
The second is valid but not the first.
Both are invalid.

✓

Answer

The first is valid but not the second.

For a point inside the elevator, pressure can be defined as $\text{P}=\lim_\limits{\triangle\text{s}\rightarrow0}\frac{\text{F}}{\triangle\text{s}}\cdot$ It is independent of the acceleration of the elevator.
The modified form of the second equation, which will be valid in the given case, is given.$\text{P}_1-\text{P}_2=\text{p}(\text{g}+\text{a}_0)\text{z}$
Here, acceleration a₀(say) due to elevator accelerating upwards is also taken into account.

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