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Flashcards in Pressure Deck (28)
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1

Why do polar explorers use snow shoes or skis?

There is a larger surface area so the weight is more spread out and they don't sink into the snow

2

Pressure is the ________ that acts on each ________ ________ of an object

Force
Square metre

3

Pressure is sometimes described as the ______________ of force

Concentration

4

The scientific unit for pressure is the ________

Pascal

5

A gas exerts pressure when its molecules are in ________ _________

Constant motion

6

When the gas particles collide with a surface they apply a ______ to it

Force

7

A denser gas will apply ________ force as there'll be more particles hitting each _______ ______

Greater
Unit area

8

Why does atmospheric pressure decrease when there is an increase in height?

The number of air molecules decreases the higher up you go so there is less air pushing down on it than there would be at a lower height

9

What is density measured in?

Kg/m3

Kilograms per metre cubed

10

Name two illnesses that can be caused by changes in pressure

Altitude sickness
The Bends

11

What can be used to measure pressure?

Manometers and Barometers

12

What are Barometers used for?

Predicting changes in weather

13

What happens to pressure if you go:

A)Under Water
B)Up a mountain

A)Increases
B)Decreases

14

The ______ the depth, the greater the pressure

Greater

15

Find the area when:

Force = 506N
Pressure = 0.674 kPa

0.75 m2

16

Find the force when:

Pressure = 10200 Pa
Area = 560 cm2

57120 N

17

Find the pressure when:

Force = 2N
Area = 4 cm2

5000 Pa

18

Why do gases exert pressure?

Use key scientific vocabulary

The particles move in RANDOM MOTION and COLLIDE with the sides of their container. This puts FORCE and EXERTS PRESSURE

19

In a fluid, the particles are in constant, _________ motion

Random

20

When a particle _________ with another object it exerts a force. The combined effect of all the particle collisions causes the __________ on objects in contact with the fluid

Collides
Pressure

21

Why does heating a fluid increase the pressure?

The particles are moving faster

22

Why do liquids usually exert greater pressure than gases?

The particles in a liquid are closer together

23

What provides the upthrust?

The weight of the fluid displaced

24

The weight and upthrust are unbalanced on floating objects

True or False?

False

The weight and upthrust on floating objects are balanced

25

How do boats float?

The large volume of water displaced by a boat provides the necessary upthrust

26

What causes atmospheric pressure?

The weight of the air above us

27

What is the air pressure at sea level?

1 atmosphere

OR

100 kPa

28

Why aren't we crushed by air pressure?

The air pressure inside our bodies matched the air pressure outside our bodies