Explain why (a) the blood pressure is humans is greater at the feet than at the brain.
(b) Atmospheric pressure at a height of about 6 km decreases to nearly half its value at the sea level through the 'height' of the atmospheric is more than 100 km.
(c) Hydrostatic pressure is a scalar quantity even though pressure is force divded by area , and force is a vector.

Explanation

(a) The height of the blood column in the human body is more at feet than at the brain , that is why, the blood exerts more pressure at the feet than at the brain. ` ( :' pressure = h rho g)`
(b) We know that the density of air si maximum near the surface of earth and decreases rapidly with height and at a height of about 6km, it decreases ot nearly half its value at the sea level. Beyoud 6 km height the density of air decreases very slowly with height. due to this reason, the atmospheric pressure at a height of about 6 km decreases to nearly half of its value at sea level .
(c ) Since due to applied force on liquid , the pressure is transmitted equally in all directions inside the liquid. that is why there is no fixed direction for the pressure due to liquid. hence hydrostic pressure is a scalar quantity.