Unit 3 - Forces, Fluids, And Density Flashcards Preview

SHS (Zielke) Science 8 > Unit 3 - Forces, Fluids, And Density > Flashcards

Flashcards in Unit 3 - Forces, Fluids, And Density Deck (39):
1

Particle Theory of Matter

Theory that explains the behaviour of solids, liquids, and gases; it states that all matter is made up of tiny moving particles that attract each other and have spaces between them (Pg. 182)

2

Solid

Particles are close together and in a fixed place.

3

Liquid

Particles are close together but can slide around and over each other.

4

Gas

Particles are far apart and move rapidly.

5

Fluid

Any matter that has no fixed shape, can flow, and takes the shape of its container; any substance in a gas or liquid state (Pg. 183)

6

Viscosity

A liquid’s internal resistance or friction that keeps it from flowing (Pg. 185)

7

Weight

Measure of the force of gravity on an object (Pg. 194)

8

Mass

Measurement of the amount of matter that is in an object (Pg. 194)

9

Density

Mass per unit of volume; measure by dividing the mass of a substance by its volume; the amount of matter or number of particles in a given volume (Pg. 194)

10

Volume

The amount of space taken up by an object (Pg. 194)

11

Force

Push or pull that tends to cause an object to move or change its motion; measured in Newtons (N) (Pg. 214)

12

Buoyant Force

Upward force that a liquid exerts on an object, opposite to the pull of gravity on an object in a liquid; an important property of fluids; the property that causes a ship to float in water (Pg. 214)

13

Gravitational Force

Force trying to pull an object down to the center of the Earth (Pg. 214)

14

Pressure

A measure of the amount force applied to a particular area; measure in pascals (Pa) (Pg. 236)

15

Compression

Result when a force pushes on an object (Pg. 242)

16

Hydraulic Device

Devices that use water or some other liquid in motion to do useful work (Pg. 236)

17

Hydraulic Fluid

The liquid part put into a hydraulic system (Pg. 248)

18

Hydraulic System

System that uses liquids in a confined space to transfer forces; operates according to Pascal’s Law (Pg. 248)

19

Pneumatic Devices

Devices that use air or other gases in a confined space or transmit forces (Pg. 236)

20

Pneumatic Systems

Confined, pressurized systems that use air or other gases to transmit forces (Pg. 252)

21

Variables

Things that can be changed in a scientific experiment (Pg. 186)

22

Fair Test

Experiment in which only one variable is changed at a time (Pg. 186)

23

Balanced Forces

Opposite and equal forces acting on an object; for an object to remain suspended in water, the downward force of gravity must be balanced by and equal upward force (Pg. 214)

24

Newton (N)

The unit used in science for gravitational force (Pg. 214)

25

Personal Flotation Device (PFD)

A safety device designed to keep a person afloat in water (Pg. 216)

26

Archimedes’ Principle

Buoyant force acting on an object equals the weight, or gravitational force, of the fluid displaced by the object (Pg. 218)

27

Swim Bladder

A specialized organ in many fish, containing a mixture of air and water; this organ allows the fish to control it’s swimming depth (Pg. 221)

28

Ballast Tank

Tanks in submarines that enable the submarine to dive and resurface; ballast tanks depend on a feature similar to a swim bladder in fish (Pg. 221)

29

Displacement Method

Method of measuring volume which involves placing an object in a container of water and measuring the amount of water moved (displaced); alternatively, placing an object into a container full of water and measuring the volume of the overflow (Pg. 330)

30

Contact Force

Force exerted when two objects are touching one another (Pg. 230)

31

Non-contact Force

Force exerted between two things that are not touching (Pg. 230)

32

Pascal’s Law

When pressure is applied to a liquid in a container, the pressure and force is transmitted equally and undiminished throughout the liquid; an enclosed liquid transmits pressure equally in all directions (Pg. 246)

33

Incompressible

Unable to be compressed easily (Pg. 246)

34

Input Device

Device that puts information into a system (Pg. 249)

35

Output Device

Part of a system that responds to an input (Pg. 249)

36

Mechanical Advantage

The ability to produce an output force larger than the input force (Pg. 250)

37

Pump

A machine or device that displaces fluid by mechanical or physical action (Pg. 250)

38

Closed Hydraulic System

Hydraulic systems where the liquid cannot leave the system (Pg. 251)

39

Open Hydraulic System

Hydraulic systems where the liquid can leave the system; these can be used to transport fluids; Ex: hand pumps for water (Pg. 251)