Pressure

Question 1

what is pressure?

Answer 1

The force per unit area

Question 2

how do you calculate pressure?

Answer 2

Area (m2)

Question 3

what is pressure measured in?

Answer 3

newtons per square metre (N/m2) or pascals (Pa)

Question 4

what does weight spread over a small area produce?

Answer 4

high pressure

Question 5

what does weight spread over a large area produce?

Answer 5

low pressure

Question 6

what does pressure in liquids depend on?

Answer 6

depth - the greater the depth, the greater the pressure

and the density of the liquid

Question 7

how does pressure act?

Answer 7

equally in all directions

Question 8

does air have weight?

Answer 8

yes

Question 9

does air have mass?

Answer 9

yes

Question 10

does air occupy space?

Answer 10

yes

Question 11

give an example of an experiment you could do to show that air has weight

Answer 11

put an inflated balloon on a balance

Question 12

give an example of an experiment you could do to show that air takes up space

Answer 12

put a glass in a basin a quarter filled with water with a plastic tube running into it. blow water into it and the water level rises on the outside

Question 13

what is atmospheric pressure due to the weight of air presing down on the earth

Answer 13

the weight of air pressing down on the earth

Question 14

what happens to atmospheric pressure as we increase our height above sea level?
why?

Answer 14

it decreases

the weight of air decreases

Question 15

what is used to measure atmospheric pressure?

Answer 15

a barometer

Question 16

what weather does high atmospheric pressure bring?

Answer 16

good, settled weather

Question 17

what weather does low atmospheric pressure bring?

Answer 17

bad, unsettled weather

Question 18

give three everyday applications of pressure

Answer 18

Hydraulics forces liquids from one size space to another size e.g. car brakes
Water supply system: The higher a reservoir above a house, the greater the water pressure in the house.
Medicine:Blood pressure is an indication of how healthy a person is

Question 19

what does the effect of a force on a surface depend on?

Answer 19

how it is spread out over the surface

Question 20

give an example of weight spread over a small area and it’s effects

Answer 20

The woman with the stiletto heels can cause damage to floor covering
as her weight is concentrated over a small area.

Question 21

give an example of pressure in water

Answer 21

When underwater, a diver experiences pressure from the liquid all around him. The deeper he dives, the greater is the pressure exerted

Question 22

does with or shape affect pressure?

Answer 22

no

Question 23

is the pressure in a liquid equally or unequally distributed?

Answer 23

equally

Question 24

is air a fluid?

Answer 24

yes

Question 25

how does air exert pressure?

Answer 25

in the same way as liquids

Question 26

do the experiment to show that air exerts pressure

Answer 26

.

Question 27

does the atmosphere exert pressure?

Answer 27

yes

Question 28

do the experiment to show that air has mass

Answer 28

.

Question 29

does air have volume?

Answer 29

yes

Question 30

do the experiment to show that air has volume

Answer 30

.

Question 31

give two examples of atmospheric pressure

Answer 31

rubber suckers | a card on a glass jar of water

Question 32

name a type of barometer

Answer 32

a mercury barometer | ananeroid barometer

Question 33

describe how a mercury barometer works

Answer 33

atmospheric pressure holds up the column of mercury

Question 34

what does normal atmospheric pressure hold up?

Answer 34

Normal atmospheric pressure holds up a column of 76 cm of mercury.

Question 35

what happens in a mercury barometer when atmspheric pressure increases?

Answer 35

When atmospheric pressure increases, the mercury rises slightly up the tube.

Question 36

what happens in a mercury barometer when atmspheric pressure decreases?

Answer 36

When atmospheric pressure decreases, the mercury falls slightly down the tube.

Question 37

what is special about the aneroid barometer?

Answer 37

it uses no liquid

Question 38

what is an aneroid barometer made of?

Answer 38

a partially evacuated corrugated box

Question 39

what happens to the aneroid barometer if the atmospheric pressure increases?

Answer 39

If atmospheric pressure increases, the box is crushed slightly, causing the pointer to move.

Question 40

what happens to the aneroid barometer if the atmospheric pressure decreases?

Answer 40

When the pressure decreases, the pointer moves the other way

Question 41

what is the instrument used by pilots to measure height above sea level and how is it used?

Answer 41

When we move higher above sea level: The atmospheric pressure decreases. An instrument called an altimeter is used by pilots to measure height above sea level. It does this by measuring the pressure on a barometer.

Question 42

what happens in the weather when the atmospheric pressure is high?

Answer 42

When the atmospheric pressure is high: Water vapour does not rise from the ground. This means that rain clouds do not form and the weather is fine and sunny

Question 43

what happens to water vapour when the atmospheric pressure is high?

Answer 43

it does not rise from the ground

Question 44

what happens in the weather when the atmospheric pressure is low?

Answer 44

When the atmospheric pressure is low: Water vapour rises up from the ground. Rain clouds form, which may cause rain

Question 45

what happens to water vapour when the atmospheric pressure is low?

Answer 45

When the atmospheric pressure is low: | Water vapour rises up from the ground

Question 46

give the three points on high pressure

Answer 46

high pressure heavy air (sinking) happy weather

Question 47

give the three points on low pressure

Answer 47

Low pressure Light air (rising) Lousy weather

Question 48

what do the lines on a weather chart show?

Answer 48

The lines on a weather chart show areas of equal pressure.

Question 49

What shows areas of equal pressure on a weather chart?

Answer 49

isobars

Question 50

what are the lines on a weather chart called?

Answer 50

isobars

Question 51

what are isobars shown as on weather charts?

Answer 51

Isobars are shown on weather charts as areas of high pressure and low pressure.