Pressure in fluids and atmospheric pressure

Question 1

thrust

Answer 1

Thrust is the force acting normally on a surface.

Question 2

how is thrust exerted by a body?

Answer 2

thrust exerted by a body is equal to its weight

Question 3

Thrust is ______ quantity

Answer 3

vector

Question 4

SI unit of thrust

Answer 4

Newton

Question 5

C.G.S unit of thrust

Answer 5

dyne

Question 6

Relationship between SI and cgs unit of thrust

Answer 6

1 N = 10^5 dyne

Question 7

1 kgf = _____________ Newton

Answer 7

9.8

Question 8

1 gf = ___________ dyne

Answer 8

980

Question 9

what does the impact of thrust depend upon?

Answer 9

area on which it acts

Question 10

pressure

Answer 10

thrust / area

Question 11

si unit of pressure

Answer 11

pascal

Question 12

pascal formula

Answer 12

1 N/m^2

Question 13

pascal definition

Answer 13

one pascal is the pressure exerted on a surface of area 1m^2 by a force on 1 newton acting normaly on it.

Question 14

What is 1 bar equivalent to in terms of N/m²?

Answer 14

1 bar = 10⁵ N/m²

Question 15

What is 1 millibar equivalent to in terms of bar and N/m²?

Answer 15

1 millibar = 10⁻³ bar = 10² N/m²

Question 16

In which unit is atmospheric pressure often expressed?

Answer 16

Atmospheric pressure is often expressed in terms of the height of a mercury column in a barometer.

Question 17

What is 1 atmosphere (atm) equal to in terms of mercury column height?

Answer 17

1 atm = 0.76 m of Hg

Question 18

What is 1 atmosphere (atm) in terms of pascals (Pa)?

Answer 18

1 atm = 1.013 × 10⁵ Pa

Question 19

What is 1 torr equivalent to in terms of atm?

Answer 19

1 torr = 1 atm / 760

Question 20

fluids

Answer 20

A fluid is any substance that can flow, encompassing both liquids and gases.

Question 21

Pressure in Fluids (direction)

Answer 21

A solid exerts pressure only on the surface it is placed on, primarily at its bottom.
A fluid, however, exerts pressure not just on the bottom of its container but also on the walls of the container due to its ability to flow. Hence, a fluid exerts pressure in all directions.
Conclusion: A fluid contained in a vessel exerts pressure at all points and in all directions.

Question 22

Experimental Demonstration: (pressure in all directions)

Answer 22

Setup: Take a vessel filled with a liquid (e.g., water) and place it on a horizontal surface. Make several small holes at different points in the walls of the vessel, below the free surface of the liquid.
Observations: Liquid Spurting: The liquid spurts out through each hole. This indicates that the liquid exerts pressure at each point on the vessel’s walls. Feeling Thrust: When a finger is placed on any hole, a thrust due to the liquid is felt. This demonstrates that the liquid in the vessel exerts a thrust at all points below its free surface. The thrust per unit area at a point corresponds to the pressure of the liquid at that point. Distance of Flow: By noting the distance from the bottom of the vessel to the point where the liquid from a hole strikes the horizontal surface, it is observed that as the depth of the hole below the free surface of the liquid increases, the throw of the liquid also increases. This shows that liquid pressure at a point increases with the depth of the point from its free surface.