a) The pressure is the physical quantity that informs us how much force is applied perpendicular to the surface unit.
b) The pressure is equal to the quotient of the force and the surface area.
c) The pressure due to the weight of the non‑moving (static) fluid is called hydrostatic pressure.
d) The formula for calculating the hydrostatic pressure is $p=d·g·h$.
e) Atmospheric pressure is the pressure exerted by the atmosphere on the bodies within the atmosphere or on the surface of the Earth. Atmospheric pressure - like hydrostatic pressure - is related to the weight of the air above the level at which we measure the pressure. The closer to the Earth's surface, the higher the atmospheric pressure, and conversely - it is lower on mountain peaks than in the valleys.
f) The basic pressure unit in the SI system is pascal (1 Pa).

The pressure can be given in such units as:

• atmosphere - atm

• millimeters of mercury - mm Hg

• pascal - Pa

The relationship between these pressure units:

$1atm=760mmHg=1013,25hPa=101325Pa$

a) Hand‑set pointer, pointer, lever, flexible metal box.
b) The flexible metal box moves the lever when the pressure changes. The lever movement causes the spindle of the pointer to rotate. In order to recognize whether the pressure increased or decreased, the pointer is compared to the hand‑set pointer.
c) Torricelli's mercury barometerbarometerbarometer, analogue barometer, electronic barometer.

a) $1atm=760mmHg=1013,25hPa$, therefore:

$780mmHg=780mmHg\cdot \frac{101325Pa}{760mmHg}=103991Pa=1039,91hPa$

b) $980Pa=980Pa\cdot \frac{760mmHg}{101325Pa}=7,351mmHg$

a) False.
b) True.
c) True.
d) True.

The pressure is about 300 kPa. A man cannot dive at this depth without diving equipment. Safe depth for humans is about 30 m.

Measure the height of the liquid column h. Find in the tables the liquid density d and the value of standard gravity g. Substitute the values obtained into the formula:

Check the unit calculation to get the result in pascal.