Unit 3 - Forces, Fluids, And Density

Question 1

Particle Theory of Matter

Answer 1

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)

Question 2

Solid

Answer 2

Particles are close together and in a fixed place.

Question 3

Liquid

Answer 3

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

Question 4

Gas

Answer 4

Particles are far apart and move rapidly.

Question 5

Fluid

Answer 5

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)

Question 6

Viscosity

Answer 6

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

Question 7

Weight

Answer 7

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

Question 8

Mass

Answer 8

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

Question 9

Density

Answer 9

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)

Question 10

Volume

Answer 10

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

Question 11

Force

Answer 11

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

Question 12

Buoyant Force

Answer 12

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)

Question 13

Gravitational Force

Answer 13

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

Question 14

Pressure

Answer 14

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

Question 15

Compression

Answer 15

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

Question 16

Hydraulic Device

Answer 16

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

Question 17

Hydraulic Fluid

Answer 17

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

Question 18

Hydraulic System

Answer 18

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

Question 19

Pneumatic Devices

Answer 19

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

Question 20

Pneumatic Systems

Answer 20

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

Question 21

Variables

Answer 21

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

Question 22

Fair Test

Answer 22

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

Question 23

Balanced Forces

Answer 23

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)

Question 24

Newton (N)

Answer 24

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

Question 25

Personal Flotation Device (PFD)

Answer 25

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

Question 26

Archimedes’ Principle

Answer 26

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

Question 27

Swim Bladder

Answer 27

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)

Question 28

Ballast Tank

Answer 28

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)

Question 29

Displacement Method

Answer 29

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)

Question 30

Contact Force

Answer 30

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

Question 31

Non-contact Force

Answer 31

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

Question 32

Pascal’s Law

Answer 32

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)

Question 33

Incompressible

Answer 33

Unable to be compressed easily (Pg. 246)

Question 34

Input Device

Answer 34

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

Question 35

Output Device

Answer 35

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

Question 36

Mechanical Advantage

Answer 36

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

Question 37

Pump

Answer 37

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

Question 38

Closed Hydraulic System

Answer 38

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

Question 39

Open Hydraulic System

Answer 39

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