Question

EXERCISES
(b) Atmospheric pressure at a height of about 6 km decreases to nearly hallo-
(a) The blood pressure in humans is greater at the feet than at the brain
its value at the sea level, though the height of the atmosphere is more
0.
Explain why
10.
100 km
(c) Hydrostatic pressure is a scalar quantity even though pressure is force
divided by area.
Explain why
10
(a) The angle of contact of mercury with glass is obtuse, while that of water
with glass is acute.
(b) Water on a clean glass surface tends to spread out while mercury on the i
same surface tends to form drops. (Put differently, water wets glass whil
mercury does not.)
(c) Surface tension of a liquid is independent of the area of the surface
(d) Water with detergent disolved in it should have small angles of contact,
(e) A drop of liquid under no external forces is always spherical in shape
Fill in the blanks using the word(s) from the list appended with each stateme
(a) Surface tension of liquids generally
with te​

Answer 1

Answer:

(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 =ρgh )

where h= height, ρ = density of liquid and g= accleration due to gravity)

(b) Density of air decreases very rapidly with increase in height and reduces to nearly half its value at the sea level at a height of about 6 km. After 6 km, the density of air decreases but rather very slowly.

(c) When force is applied on a liquid, then according to Pascal's Law, the pressure in the liquid is transmitted in all directions.

Hence, hydrostatic pressure does not have a fixed direction and it is a scalar physical quantity.

Explanation:

follow me

like my answer