Pressure

Question 0

What is the equation for pressure (on a surface)?

Answer 0

P = F/A

Question 1

What is the standard unit for area?

Answer 1

m2

Question 2

What are the two units for pressure?

Answer 2

N/m2 and Pa

Question 3

How do you convert from cm2 to m2?

Answer 3

Divide by 10,000 (100 squared)

Question 4

Can you compress a liquid?

Answer 4

No

Question 5

Rearrange the pressure equation to have Force on its own.

Answer 5

F = P x A

Question 6

Rearrange the pressure equation to have Area on its own.

Answer 6

A = F/P

Question 7

Convert 25N into a mass (on Earth).

Answer 7

2.5kg

Question 8

How do you calculate the pressure in a liquid?

Answer 8

P = h d g

Pressure (N/m2) = height (m) x density (kg/m3) x G.F.S. (N/kg)

Question 9

What is the standard unit for volume?

Answer 9

m3

Question 10

What is the mass of water per m3?

Answer 10

1m3 = 1000kg or 1 tonne

Question 11

Rearrange the equation for pressure in a liquid so that Height is on its own.

Answer 11

h = p/d/g

Question 12

What is the equation for energy (work done)?

Answer 12

E = F x d

Question 13

What happens to air pressure with altitude?

Answer 13

It decreases.

Question 14

Why can high altitude cause travel illness?

Answer 14

There is not enough oxygen which can make people feel sick.

Question 15

What is 1 atm?

Answer 15

The mass and therefore weight of air in the column above a 1cm2 area.

Question 16

What is 1 bar and 1 atm in N/m2?

Answer 16

1 bar = 100,000 Pa

1 atm = 101,000 Pa

Question 17

What is the equation for volume?

Answer 17

V = A x D (or height)

Question 18

Why does atmospheric pressure decrease with altitude?

Answer 18

There is less air above pushing down on a certain point.

Question 19

What is pressure?

Answer 19

The ratio of force spread of an area.

Question 20

How do you convert mass into a force on earth?

Answer 20

Mass x 10 = Force on earth

Question 21

What is the equation for density?

Answer 21

Density (kg/m3) = Mass (kg) / Volume (m3)

Question 22

In a closed system of air: P1 V1 = ?

Answer 22

P1 V1 = P2 V2

e.g. If the volume of the container goes up, the pressure decreases and vice versa

Question 23

How does a hydraulic system produce an output force?

Answer 23

1) FORCE applied to MASTER
2) FORCE divided by area to create PRESSURE (P=F/A)
3) If system is completely efficient, the non-compressible liquid transfers the PRESSURE to the SLAVE
4) The PRESSURE is multiplied by the second area to create an output FORCE (P x A = F)

Question 24

What is it important to remember when using area in force equations?

Answer 24

Always convert cm2 to m2 (divide by 10,000)

Question 25

Although to go from cm2 to m2 you divide by 10,000, what is it important to remember when going from N/cm2 to N/m2?

Answer 25

Multiply by 10,000 instead

Question 26

What is the equation for work done / energy?

Answer 26

Wd (J or Nm) = Force (N) x Distance (m)