Q.Would it be easier to drink water with a straw on the top of Mount Everest?

Pressure is defined as force divided by the area over which that force acts:

$P=\frac{\text{Force}}{\text{Area}}$

The SI unit of pressure is the pascal (Pa), defined as one newton of force spread over one square metre, $1\ \text{Pa}=1\ \text{Nm}^{-2}$. In chemistry, several other pressure units remain in everyday use and each converts to the pascal by a fixed factor: 1 atmosphere (atm) = 101325 Pa; 1 millimetre of mercury (mmHg) = 133.322 Pa; 1 bar = $10^5$ Pa; 1 torr = 133.322 Pa (numerically identical to the mmHg); 1 pound per square inch (psi) = 6894.76 Pa. …