Pressure

Question 1

Pressure

Answer 1

the force applied perpendicular to the surface of an object.

unit: Pascal (N/m^2)

Question 2

1 bar

Answer 2

100 kPa

Question 3

1 atm

Answer 3

101 kPa

Question 4

1 mmHg

Answer 4

133 Pa

Question 5

Internal state of gases and fluids depends on…

Answer 5

The pressure, which again depends on their density.

Question 6

Density

Answer 6

The mass of a homogenous body divided by it’s volume.
D= m/v
If the body is inhomogeneous ( e.g: different densities at different depths of the water), this formula gives the average density.

Question 7

Density of materials depends on

Answer 7

temperature and pressure, especially when it comes to gases

Question 8

Water is most dense at

Answer 8

4 degrees celsius.

!!! Ice is lighter than water

Question 9

Hydrostatic pressure

Answer 9

Caused by the gravitational field of the earth.

W = p * h *g

The pressure in fluids ang gases is directly proportional to depth, if the density is the same at every depth

Question 10

The hydrostatic paradox

Answer 10

Hydrostatic pressure depends only on the density and the height of the fluid and is independent on the shape of the container.. Pressure of the bottom of containers with different shapes are the same, if the height of the fluid is the same. INTUITION IS WRONG

Question 11

The pressure of gases

Answer 11

particles in gases are in constant motion so they collide with each other and with the walls of the container.

the particles exert a tiny force on the walls on the container and the pressure of the gas comes from the sum of all these tiny forces.

Question 12

Atmospheric pressure

Answer 12

Decreases exponentially with elevation. The pressure of air at a given altitude is not constant but fluctuates according to local temperature and weather conditions.

Standard: 101 kPa

Question 13

Partial pressure

Answer 13

In a mixture of gases, each gas has a partial pressure which is the hypothetical pressure that gas if it alone occupied the volume of the mixture of the same temperature. The sum of the partial pressures in a mix of gases makes up the total pressure.

Question 14

(PP) Which is the correct phrase to complete the sentence? The density of a body is independent of...
A) The material of the body
B) The temperature of the body
C) The outer pressure
D) The shape of the body

Answer 14

D ??

Question 15

(PP) Calculate the pressure when a force of 5 N is acting perpendicularly on a surface of 0,4m^2

A) 1,25 Pa
B) 12,5 Pa
C) 125 Pa
D) 1,25 kPa

Answer 15

B

Question 16

(PP) Which statement is true about water at 4 degrees celsius?

A) Weight is maximal
B) Mass is maximal
C) Partial pressure is maximal
D) Density is maximal

Answer 16

D

Question 17

(PP) What is the hydrostatic pressure exerted by 20 cm high column of mercury?
A)26,68 kPa
B) 1962 Pa
C) 2668 Pa
D) 20 mmHg

Answer 17

C

Question 18

(PP) Which of the following units of pressure is the largest?
A) 1 Pa
B) 1 bar
C) 1 ATM
D) 1 mmHg

Answer 18

C

1 Pa = 101 kPa