Physical Science 9 final

Difference Between Displacement and Distance

Displacement: straight line start to finish; Distance: actual path walked

Speed

Rate of change of position of an object in any direction (m/s)

Velocity

Speed in combination with direction of motion of an object

Instantaneous Speed Measurement

Measured at a particular instant

Slope of a Line on Distance-Time Graph

Indicates speed of an object

Acceleration

Capacity to gain speed within a short time (m/s squared)

Free Fall

Objects fall towards Earth due to Earth's gravitational pull

Speed of Objects in Free Fall

9.8m/s squared

Difference Between Positive and Negative Acceleration

Positive: speeding up; Negative: slowing down

Force

Push or pull that acts on an object (newton)

Newton's First Law

An object at rest remains at rest, and an object in motion remains in motion

Newton's Second Law

Describes how force exerted on an object, its mass, and acceleration are related

Newton's Third Law

Force cannot exist on its own; they must exist in pairs

Why don't Reaction-Action Forces Cancel Each Other Out

Action and reaction do not act on the same object

Momentum

The product of an object's mass and velocity

Newton's Law of Universal Gravitation

Universal forces act over a distance between particles of matter

Centripetal Force

The force exerted on the center of a curved path

Work

Transfer of energy

Power

The rate of doing work

Ways to Increase Power

Do work at a faster rate or increase the amount of work

Can Work Output Ever Be Greater Than Work Input?

No, because some work is lost to friction

Is Efficiency Always Less Than 100%?

Yes

What Is a Lever?

Simple machine with a fulcrum

Three Types of Levers

First class (fulcrum in middle)

Second class (output in the middle)

Third class (input in the middle)

Wheel and Axle

2 disks or cylinder each with a different radius

What Is an Inclined Plane?

Slanted surface along which force moves an object to a different elevation

What Is a Wedge?

V-shaped objects whose two sides are inclined planes

What Is a Screw?

Cylinder with an inclined plane wrapped around it

What Is a Pulley?

A rope and wheel that's pulled to make work easier

What Is a Fixed Pulley?

Attached in a fixed location

Moveable Pulley

Attached to the object being pulled rather than a fixed location

Compound Machine

Combination of two or more simple machines

Kenetic Energy

Energy of motion

Potential Energy

Energy stored as a result of position or shape

Gravitational Potential Energy

Depends on height of an object

Elastic Potential Energy

Potential energy of an object that is stretched or compressed

Mechanical Energy

Total kinetic and potential energy of an object

Thermal Energy

Total potential and kinetic energy of particles in an object

Chemical Energy

Energy stored in chemical bonds

Electrical Energy

Energy associated with electric charge

Electromagnetic

Energy that travels as waves through space

Nuclear Energy

Energy stored in nucleus of atom

Law of Conservation of Energy

Energy cannot be created or destroyed

Heat

The transfer of thermal energy from one object to another

Temperature Related to Average Particle Energy

Kinetic

Faster Particles, Higher Temp

Higher

Heat Flows

From higher to lower temperatures

What does Thermal Energy Depend On

Mass, Temperature, Phase

What is Thermal Expansion and How Does it Occur

The increase in volume of a material due to a temperature increase

What is Specific Heat

The amount of heat needed to raise the temperature of 1 gram of a material by 1 Celsius

What Instrument is Used to Measure Heat Changes in an Object

Calorimeter

Conduction

The transfer of thermal energy through collisions in particles that make up matter

Convection

The transfer of thermal energy when particles of a fluid move from one place to another

Radiation

The transfer of energy by electromagnetic waves moving through space

List Several Good Conductors and Good Insulator

Plastic, Fiberglass, Diamond, Glass

What is a Medium

Material through which a wave will travel

Transverse Wave

Wave that vibrates at a right angle, has crests and troughs

Longitudinal Wave

Wave travels parallel to its direction (compression and rarefaction)

Surface Wave

Wave that travels along the surface separating two media

Frequency

Number of complete cycles in a given time unit (Hz)

Period

Time of one wave (sec)

Relationship between Periods and Frequency

Inversely related

Wavelength

Distance between a point on one wave and the same point on the next wave

Amplitude of Transverse and Longitudinal Waves

Rest position to compression

Reflection

Parallel light waves striking a surface and reflecting in many directions

Refraction

Light passing at an angle from one medium to another

Diffraction

Bending of a wave around an obstacle

How is Reflection Different from Refraction and Diffraction

Wave still continues forward but for reflection it goes back in opposite way

Constructive Wave Interference

2 waves overlap to produce a wave with a larger displacement

Destructive Wave Interference

2 waves overlap to produce a wave with a smaller displacement

Sound Waves are What Type of Wave

Longitudinal

What Type of Medium Does a Mechanical Wave Travel the Fastest

Solid

What is the Angle of Incidence

The angle of incident ray makes with the optical axis-incidence

What is the Angle of Reflection

The angle the reflected ray makes with the optical axis

What is the Law of Reflection

The angle of reflection is equal to the angle of incidence

What Causes Light to Refract

Medium

What Is a Plane Mirror

Reflective surface with a flat shape

What Is a Concave Mirror

Mirror with an inward-curved surface

What Is a Convex Mirror

Mirror with an outward-curved surface

Type of Image from Concave Mirror

Can form real or virtual images

Type of Image from Convex Mirror

Forms virtual images

Difference Between Lenses and Mirrors

Lenses are transparent, have one or two curves, while mirrors do not

Light Passing Through a Lens

Bends or refracts

Image from Concave Lens

Forms virtual images

Image from Convex Lens

Can form real or virtual images

Total Internal Reflection

Complete reflection of light back into the same medium

How Fiber Optics Work

Carry information as light

Electromagnetic Waves

Travel at the same speed but vary in wavelength and frequency

Light Properties

Can be treated as both a wave and stream of particles

EM Spectrum Order (Longest to Shortest Wavelength)

Radio waves, microwaves, infrared, visible light, ultraviolet, x-ray, gamma ray

EM Spectrum Order (Highest to Lowest Frequency)

Gamma ray, x-ray, ultraviolet, visible light, infrared, microwaves, radio waves

Least Energetic EM Spectrum Part

Radio waves

Color Composition

White color is made up of all colors of the visible spectrum

Transparent Material

Allows most light to pass through, enabling clear visibility

Translucent Material

Scatters light, making objects visible but not clear or distinct

Opaque

Impenetrable to light

Light Transmission

Reflection, Refraction, Scattering

Scattering

Light redirection in a medium